diff --git a/core/modules/file/file.field.inc b/core/modules/file/file.field.inc
index e3a7d7c..a3f355f 100644
--- a/core/modules/file/file.field.inc
+++ b/core/modules/file/file.field.inc
@@ -249,7 +249,7 @@ function file_field_update(EntityInterface $entity, $field, $instance, $langcode
   }
 
   // Compare the original field values with the ones that are being saved.
-  $original = $entity->original;
+  $original = $entity->original->getBCEntity();
   $original_fids = array();
   if (!empty($original->{$field['field_name']}[$langcode])) {
     foreach ($original->{$field['field_name']}[$langcode] as $original_item) {
diff --git a/core/modules/node/tests/modules/node_access_test/node_access_test.module b/core/modules/node/tests/modules/node_access_test/node_access_test.module
index 66c6b59..38ee65c 100644
--- a/core/modules/node/tests/modules/node_access_test/node_access_test.module
+++ b/core/modules/node/tests/modules/node_access_test/node_access_test.module
@@ -17,13 +17,13 @@
 function node_access_test_node_grants($account, $op) {
   $grants = array();
   // First grant a grant to the author for own content.
-  $grants['node_access_test_author'] = array($account->uid);
+  $grants['node_access_test_author'] = array($account->id());
   if ($op == 'view' && user_access('node test view', $account)) {
     $grants['node_access_test'] = array(8888, 8889);
   }
 
   $no_access_uid = state()->get('node_access_test.no_access_uid') ?: 0;
-  if ($op == 'view' && $account->uid == $no_access_uid) {
+  if ($op == 'view' && $account->id() == $no_access_uid) {
     $grants['node_access_all'] = array(0);
   }
   return $grants;
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 4fc06f7..93bf344 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -2609,6 +2609,8 @@ function system_form_user_register_form_alter(&$form, &$form_state) {
  */
 function system_user_presave($account) {
   $config = config('system.timezone');
+  debug(get_class($account));
+  debug(print_r($account->timezone, TRUE));
   if ($config->get('user.configurable') && empty($account->timezone) && !$config->get('user.default')) {
     $account->timezone = $config->get('default');
   }
diff --git a/core/modules/translation_entity/lib/Drupal/translation_entity/Tests/EntityTranslationWorkflowsTest.php b/core/modules/translation_entity/lib/Drupal/translation_entity/Tests/EntityTranslationWorkflowsTest.php
index 9957552..741b806 100644
--- a/core/modules/translation_entity/lib/Drupal/translation_entity/Tests/EntityTranslationWorkflowsTest.php
+++ b/core/modules/translation_entity/lib/Drupal/translation_entity/Tests/EntityTranslationWorkflowsTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\translation_entity\Tests;
 
-use Drupal\user\Plugin\Core\Entity\User;
+use Drupal\Core\Entity\EntityInterface;
 
 /**
  * Tests entity translation workflows.
@@ -113,7 +113,7 @@ function testWorkflows() {
    *   The an associative array with the operation name as key and the expected
    *   status as value.
    */
-  protected function assertWorkflows(User $user, $expected_status) {
+  protected function assertWorkflows(EntityInterface $user, $expected_status) {
     $default_langcode = $this->langcodes[0];
     $languages = language_list();
     $args = array('@user_label' => $user->name);
diff --git a/core/modules/user/lib/Drupal/user/AccountFormController.php b/core/modules/user/lib/Drupal/user/AccountFormController.php
index 8f2f0c5..32fc112 100644
--- a/core/modules/user/lib/Drupal/user/AccountFormController.php
+++ b/core/modules/user/lib/Drupal/user/AccountFormController.php
@@ -146,7 +146,7 @@ public function form(array $form, array &$form_state, EntityInterface $account)
     $form['account']['roles'] = array(
       '#type' => 'checkboxes',
       '#title' => t('Roles'),
-      '#default_value' => (!$register && isset($account->roles) ? array_keys($account->roles) : array()),
+      '#default_value' => (!$register ? $account->roles : array()),
       '#options' => $roles,
       '#access' => $roles && user_access('administer permissions'),
       DRUPAL_AUTHENTICATED_RID => $checkbox_authenticated,
@@ -225,6 +225,20 @@ public function form(array $form, array &$form_state, EntityInterface $account)
   }
 
   /**
+   * Overrides Drupal\Core\Entity\EntityFormController::buildEntity().
+   */
+  public function buildEntity(array $form, array &$form_state) {
+    // Change the roles array to a list of enabled roles.
+    // @todo: Move this to an value callback on the form element.
+    if (empty($this->roles_filtered)) {
+      $form_state['values']['roles'] = array_keys(array_filter($form_state['values']['roles']));
+      $this->roles_filtered = TRUE;
+    }
+    debug($form_state['values']);
+    return parent::buildEntity($form, $form_state);
+  }
+
+  /**
    * Overrides Drupal\Core\Entity\EntityFormController::submit().
    */
   public function validate(array $form, array &$form_state) {
diff --git a/core/modules/user/lib/Drupal/user/Plugin/views/filter/Name.php b/core/modules/user/lib/Drupal/user/Plugin/views/filter/Name.php
index 9d95b65..e46265b 100644
--- a/core/modules/user/lib/Drupal/user/Plugin/views/filter/Name.php
+++ b/core/modules/user/lib/Drupal/user/Plugin/views/filter/Name.php
@@ -29,8 +29,8 @@ function value_form(&$form, &$form_state) {
     if ($this->value) {
       $result = entity_load_multiple_by_properties('user', array('uid' => $this->value));
       foreach ($result as $account) {
-        if ($account->uid) {
-          $values[] = $account->name;
+        if ($account->id()) {
+          $values[] = $account->name->value;
         }
         else {
           $values[] = 'Anonymous'; // Intentionally NOT translated.
@@ -133,8 +133,8 @@ function validate_user_strings(&$form, $values) {
 
     $result = entity_load_multiple_by_properties('user', array('name' => $args));
     foreach ($result as $account) {
-      unset($missing[strtolower($account->name)]);
-      $uids[] = $account->uid;
+      unset($missing[strtolower($account->name->value)]);
+      $uids[] = $account->id();
     }
 
     if ($missing) {
@@ -159,10 +159,10 @@ public function adminSummary() {
       $result = entity_load_multiple_by_properties('user', array('uid' => $this->value));
       foreach ($result as $account) {
         if ($account->uid) {
-          $this->value_options[$account->uid] = $account->name;
+          $this->value_options[$account->id()] = $account->label();
         }
         else {
-          $this->value_options[$account->uid] = 'Anonymous'; // Intentionally NOT translated.
+          $this->value_options[$account->id()] = 'Anonymous'; // Intentionally NOT translated.
         }
       }
     }
diff --git a/core/modules/user/lib/Drupal/user/ProfileFormController.php b/core/modules/user/lib/Drupal/user/ProfileFormController.php
index bc36fbd..c2b139d 100644
--- a/core/modules/user/lib/Drupal/user/ProfileFormController.php
+++ b/core/modules/user/lib/Drupal/user/ProfileFormController.php
@@ -30,15 +30,6 @@ protected function actions(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityFormController::buildEntity().
-   */
-  public function buildEntity(array $form, array &$form_state) {
-    // Change the roles array to a list of enabled roles.
-    $form_state['values']['roles'] = array_keys(array_filter($form_state['values']['roles']));
-    return parent::buildEntity($form, $form_state);
-  }
-
-  /**
    * Overrides Drupal\Core\Entity\EntityFormController::submit().
    */
   public function submit(array $form, array &$form_state) {
diff --git a/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php b/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
index 38ca376..a1c23e5 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserRegistrationTest.php
@@ -45,7 +45,7 @@ function testRegistrationWithEmailVerification() {
     $this->assertText(t('A welcome message with further instructions has been sent to your e-mail address.'), 'User registered successfully.');
     $accounts = entity_load_multiple_by_properties('user', array('name' => $name, 'mail' => $mail));
     $new_user = reset($accounts);
-    $this->assertTrue($new_user->status, 'New account is active after registration.');
+    $this->assertTrue($new_user->status->value, 'New account is active after registration.');
 
     // Allow registration by site visitors, but require administrator approval.
     $config->set('register', USER_REGISTER_VISITORS_ADMINISTRATIVE_APPROVAL)->save();
@@ -56,7 +56,7 @@ function testRegistrationWithEmailVerification() {
     $this->container->get('plugin.manager.entity')->getStorageController('user')->resetCache();
     $accounts = entity_load_multiple_by_properties('user', array('name' => $name, 'mail' => $mail));
     $new_user = reset($accounts);
-    $this->assertFalse($new_user->status, 'New account is blocked until approved by an administrator.');
+    $this->assertFalse($new_user->status->value, 'New account is blocked until approved by an administrator.');
   }
 
   function testRegistrationWithoutEmailVerification() {
@@ -114,7 +114,7 @@ function testRegistrationWithoutEmailVerification() {
     $edit = array(
       'status' => 1,
     );
-    $this->drupalPost('user/' . $new_user->uid . '/edit', $edit, t('Save'));
+    $this->drupalPost('user/' . $new_user->id() . '/edit', $edit, t('Save'));
     $this->drupalLogout();
 
     // Login after administrator approval.
@@ -177,16 +177,17 @@ function testRegistrationDefaultValues() {
     // Check user fields.
     $accounts = entity_load_multiple_by_properties('user', array('name' => $name, 'mail' => $mail));
     $new_user = reset($accounts);
-    $this->assertEqual($new_user->name, $name, 'Username matches.');
-    $this->assertEqual($new_user->mail, $mail, 'E-mail address matches.');
-    $this->assertEqual($new_user->theme, '', 'Correct theme field.');
-    $this->assertEqual($new_user->signature, '', 'Correct signature field.');
-    $this->assertTrue(($new_user->created > REQUEST_TIME - 20 ), 'Correct creation time.');
-    $this->assertEqual($new_user->status, $config_user_settings->get('register') == USER_REGISTER_VISITORS ? 1 : 0, 'Correct status field.');
-    $this->assertEqual($new_user->timezone, $config_system_timezone->get('default'), 'Correct time zone field.');
-    $this->assertEqual($new_user->langcode, language_default()->langcode, 'Correct language field.');
-    $this->assertEqual($new_user->preferred_langcode, language_default()->langcode, 'Correct preferred language field.');
-    $this->assertEqual($new_user->init, $mail, 'Correct init field.');
+    $this->assertEqual($new_user->name->value, $name, 'Username matches.');
+    $this->assertEqual($new_user->mail->value, $mail, 'E-mail address matches.');
+    $this->assertEqual($new_user->theme->value, '', 'Correct theme field.');
+    $this->assertEqual($new_user->signature->value, '', 'Correct signature field.');
+    $this->assertTrue(($new_user->created->value > REQUEST_TIME - 20 ), 'Correct creation time.');
+    $this->assertEqual($new_user->status->value, $config_user_settings->get('register') == USER_REGISTER_VISITORS ? 1 : 0, 'Correct status field.');
+    debug($new_user->timezone->value);
+    $this->assertEqual($new_user->timezone->value, $config_system_timezone->get('default'), 'Correct time zone field.');
+    $this->assertEqual($new_user->langcode->value, language_default()->langcode, 'Correct language field.');
+    $this->assertEqual($new_user->preferred_langcode->value, language_default()->langcode, 'Correct preferred language field.');
+    $this->assertEqual($new_user->init->value, $mail, 'Correct init field.');
   }
 
   /**
@@ -240,7 +241,7 @@ function testRegistrationWithUserFields() {
     // Check user fields.
     $accounts = entity_load_multiple_by_properties('user', array('name' => $name, 'mail' => $mail));
     $new_user = reset($accounts);
-    $this->assertEqual($new_user->test_user_field[LANGUAGE_NOT_SPECIFIED][0]['value'], $value, 'The field value was correclty saved.');
+    $this->assertEqual($new_user->test_user_field->value, $value, 'The field value was correclty saved.');
 
     // Check that the 'add more' button works.
     $field['cardinality'] = FIELD_CARDINALITY_UNLIMITED;
@@ -268,9 +269,9 @@ function testRegistrationWithUserFields() {
       // Check user fields.
       $accounts = entity_load_multiple_by_properties('user', array('name' => $name, 'mail' => $mail));
       $new_user = reset($accounts);
-      $this->assertEqual($new_user->test_user_field[LANGUAGE_NOT_SPECIFIED][0]['value'], $value, format_string('@js : The field value was correclty saved.', array('@js' => $js)));
-      $this->assertEqual($new_user->test_user_field[LANGUAGE_NOT_SPECIFIED][1]['value'], $value + 1, format_string('@js : The field value was correclty saved.', array('@js' => $js)));
-      $this->assertEqual($new_user->test_user_field[LANGUAGE_NOT_SPECIFIED][2]['value'], $value + 2, format_string('@js : The field value was correclty saved.', array('@js' => $js)));
+      $this->assertEqual($new_user->test_user_field[0]->value, $value, format_string('@js : The field value was correclty saved.', array('@js' => $js)));
+      $this->assertEqual($new_user->test_user_field[1]->value, $value + 1, format_string('@js : The field value was correclty saved.', array('@js' => $js)));
+      $this->assertEqual($new_user->test_user_field[2]->value, $value + 2, format_string('@js : The field value was correclty saved.', array('@js' => $js)));
     }
   }
 }
diff --git a/core/modules/user/lib/Drupal/user/Tests/UserRolesAssignmentTest.php b/core/modules/user/lib/Drupal/user/Tests/UserRolesAssignmentTest.php
index 349b2a9..e612374 100644
--- a/core/modules/user/lib/Drupal/user/Tests/UserRolesAssignmentTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/UserRolesAssignmentTest.php
@@ -94,10 +94,10 @@ function testCreateUserWithRole() {
   private function userLoadAndCheckRoleAssigned($account, $rid, $is_assigned = TRUE) {
     $account = user_load($account->uid, TRUE);
     if ($is_assigned) {
-      $this->assertTrue(array_key_exists($rid, $account->roles), 'The role is present in the user object.');
+      $this->assertTrue(array_search($rid, $account->roles), 'The role is present in the user object.');
     }
     else {
-      $this->assertFalse(array_key_exists($rid, $account->roles), 'The role is not present in the user object.');
+      $this->assertFalse(array_search($rid, $account->roles), 'The role is not present in the user object.');
     }
   }
 }
diff --git a/core/modules/user/lib/Drupal/user/Tests/Views/AccessTestBase.php b/core/modules/user/lib/Drupal/user/Tests/Views/AccessTestBase.php
index 5455eaa..33cad6e 100644
--- a/core/modules/user/lib/Drupal/user/Tests/Views/AccessTestBase.php
+++ b/core/modules/user/lib/Drupal/user/Tests/Views/AccessTestBase.php
@@ -54,11 +54,11 @@ protected function setUp() {
 
     $this->adminUser = $this->drupalCreateUser(array('access all views'));
     $this->webUser = $this->drupalCreateUser();
-    $this->webRole = current($this->webUser->roles);
+    $this->webRole = $this->webUser->roles[0];
 
     $this->normalRole = $this->drupalCreateRole(array());
     $this->normalUser = $this->drupalCreateUser(array('views_test_data test permission'));
-    $this->normalUser->roles[$this->normalRole] = $this->normalRole;
+    $this->normalUser->getOriginalEntity()->roles[2] = $this->normalRole;
     // @todo when all the plugin information is cached make a reset function and
     // call it here.
   }
diff --git a/core/modules/user/lib/Drupal/user/Tests/Views/HandlerFieldRoleTest.php b/core/modules/user/lib/Drupal/user/Tests/Views/HandlerFieldRoleTest.php
index 55ec424..7c70baa 100644
--- a/core/modules/user/lib/Drupal/user/Tests/Views/HandlerFieldRoleTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/Views/HandlerFieldRoleTest.php
@@ -41,9 +41,9 @@ public function testRole() {
     $this->drupalCreateRole(array('access content'), $rolename_not_assigned, $rolename_not_assigned);
 
     // Add roles to user 1.
-    $user = user_load(1);
-    $user->roles[$rid_a] = $rolename_a;
-    $user->roles[$rid_b] = $rolename_b;
+    $user = entity_load('user', 1);
+    $user->roles[1]->value = $rolename_a;
+    $user->roles[2]->value = $rolename_b;
     $user->save();
 
     $view = views_get_view('test_views_handler_field_role');
diff --git a/core/modules/user/lib/Drupal/user/UserStorageController.php b/core/modules/user/lib/Drupal/user/UserStorageController.php
index 20978c8..fdb7056 100644
--- a/core/modules/user/lib/Drupal/user/UserStorageController.php
+++ b/core/modules/user/lib/Drupal/user/UserStorageController.php
@@ -26,17 +26,17 @@ function attachLoad(&$queried_users, $load_revision = FALSE) {
     foreach ($queried_users as $key => $record) {
       $queried_users[$key]->roles = array();
       if ($record->uid) {
-        $queried_users[$record->uid]->roles[DRUPAL_AUTHENTICATED_RID] = DRUPAL_AUTHENTICATED_RID;
+        $queried_users[$record->uid]->roles[] = DRUPAL_AUTHENTICATED_RID;
       }
       else {
-        $queried_users[$record->uid]->roles[DRUPAL_ANONYMOUS_RID] = DRUPAL_ANONYMOUS_RID;
+        $queried_users[$record->uid]->roles[] = DRUPAL_ANONYMOUS_RID;
       }
     }
 
     // Add any additional roles from the database.
     $result = db_query('SELECT rid, uid FROM {users_roles} WHERE uid IN (:uids)', array(':uids' => array_keys($queried_users)));
     foreach ($result as $record) {
-      $queried_users[$record->uid]->roles[$record->rid] = $record->rid;
+      $queried_users[$record->uid]->roles[] = $record->rid;
     }
 
     // Call the default attachLoad() method. This will add fields and call