diff --git a/core/lib/Drupal/Core/CoreBundle.php b/core/lib/Drupal/Core/CoreBundle.php
index bbc4e2e..d9b19e9 100644
--- a/core/lib/Drupal/Core/CoreBundle.php
+++ b/core/lib/Drupal/Core/CoreBundle.php
@@ -11,6 +11,7 @@
 use Drupal\Core\DependencyInjection\Compiler\RegisterMatchersPass;
 use Drupal\Core\DependencyInjection\Compiler\RegisterNestedMatchersPass;
 use Drupal\Core\DependencyInjection\Compiler\RegisterSerializationClassesPass;
+use Drupal\Core\DependencyInjection\Compiler\RegisterRouteLoadersPass;
 use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Reference;
@@ -72,7 +73,14 @@ public function build(ContainerBuilder $container) {
       ->addArgument(new Reference('database'));
     $container->register('router.builder', 'Drupal\Core\Routing\RouteBuilder')
       ->addArgument(new Reference('router.dumper'))
-      ->addArgument(new Reference('lock'));
+      ->addArgument(new Reference('lock'))
+      // Placeholder argument replaced with services tagged 'route_loader' by
+      // the RegisterRouteLoadersPass compiler pass.
+      ->addArgument(array())
+      ->addArgument(new Reference('dispatcher'));
+    $container->register('router.loader.yaml', 'Drupal\Core\Routing\YamlRouteLoader')
+      ->addTag('route_loader');
+    $container->addCompilerPass(new RegisterRouteLoadersPass());
 
     $container->register('matcher', 'Drupal\Core\Routing\ChainMatcher');
     $container->register('legacy_url_matcher', 'Drupal\Core\LegacyUrlMatcher')
diff --git a/core/lib/Drupal/Core/DependencyInjection/Compiler/RegisterRouteLoadersPass.php b/core/lib/Drupal/Core/DependencyInjection/Compiler/RegisterRouteLoadersPass.php
new file mode 100644
index 0000000..338e538
--- /dev/null
+++ b/core/lib/Drupal/Core/DependencyInjection/Compiler/RegisterRouteLoadersPass.php
@@ -0,0 +1,65 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\Core\DependencyInjection\Compiler\RegisterRouteLoadersPass.
+ */
+
+namespace Drupal\Core\DependencyInjection\Compiler;
+
+use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+
+/**
+ * Adds services tagged 'route_loader' to the route builder.
+ */
+class RegisterRouteLoadersPass implements CompilerPassInterface {
+
+  /**
+   * Adds services to the route builder.
+   *
+   * @param \Symfony\Component\DependencyInjection\ContainerBuilder $container
+   *   The container to process.
+   */
+  public function process(ContainerBuilder $container) {
+    $definition = $container->getDefinition('router.builder');
+
+    // Retrieve registered route loaders from the container.
+    foreach ($container->findTaggedServiceIds('route_loader') as $id => $attributes) {
+      $priority = isset($attributes[0]['priority']) ? $attributes[0]['priority'] : 0;
+      $loaders[$priority][] = new Reference($id);
+    }
+
+    // Add the registered loaders to the route builder as the 3rd argument.
+    if (!empty($loaders)) {
+      $definition->replaceArgument(2, $this->sort($loaders));
+    }
+  }
+
+  /**
+   * Sorts by priority.
+   *
+   * Order services from highest priority number to lowest (reverse sorting).
+   *
+   * @param array $services
+   *   A nested array keyed on priority number. For each priority number, the
+   *   value is an array of Symfony\Component\DependencyInjection\Reference
+   *   objects, each a reference to a route loader service.
+   *
+   * @return array
+   *   A flattened array of Reference objects from $services, ordered from high
+   *   to low priority.
+   */
+  protected function sort($services) {
+    $sorted = array();
+    krsort($services);
+
+    // Flatten the array.
+    foreach ($services as $a) {
+      $sorted = array_merge($sorted, $a);
+    }
+
+    return $sorted;
+  }
+}
diff --git a/core/lib/Drupal/Core/Routing/RouteBuildEvent.php b/core/lib/Drupal/Core/Routing/RouteBuildEvent.php
new file mode 100644
index 0000000..017b83a
--- /dev/null
+++ b/core/lib/Drupal/Core/Routing/RouteBuildEvent.php
@@ -0,0 +1,54 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Routing\RouteBuildEvent.
+ */
+
+namespace Drupal\Core\Routing;
+
+use Symfony\Component\EventDispatcher\Event;
+use Symfony\Component\Routing\RouteCollection;
+
+/**
+ * Represents route building information as event.
+ */
+class RouteBuildEvent extends Event {
+
+  /**
+   * The route collection.
+   *
+   * @var \Symfony\Component\Routing\RouteCollection
+   */
+  protected $routeCollection;
+
+  /**
+   * The module name that provides the route.
+   *
+   * @var string
+   */
+  protected $module;
+
+  /**
+   * Constructs a RouteBuildEvent object.
+   */
+  public function __construct(RouteCollection $route_collection, $module) {
+    $this->routeCollection = $route_collection;
+    $this->module = $module;
+  }
+
+  /**
+   * Gets the route collection.
+   */
+  public function getRouteCollection() {
+    return $this->routeCollection;
+  }
+
+  /**
+   * Gets the module that provides the route.
+   */
+  public function getModule() {
+    return $this->module;
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Routing/RouteBuilder.php b/core/lib/Drupal/Core/Routing/RouteBuilder.php
index 3a27767..873b262 100644
--- a/core/lib/Drupal/Core/Routing/RouteBuilder.php
+++ b/core/lib/Drupal/Core/Routing/RouteBuilder.php
@@ -7,8 +7,11 @@
 
 namespace Drupal\Core\Routing;
 
-use Drupal\Core\Lock\LockBackendInterface;
 use Symfony\Component\Routing\Matcher\Dumper\MatcherDumperInterface;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\Routing\RouteCollection;
+
+use Drupal\Core\Lock\LockBackendInterface;
 
 /**
  * Managing class for rebuilding the router table.
@@ -33,16 +36,39 @@ class RouteBuilder {
   protected $lock;
 
   /**
+   * An array of \Drupal\Core\Routing\RouteLoaderInterface objects.
+   *
+   * During route rebuilding, each loader is invoked for each enabled Drupal
+   * module.
+   *
+   * @var array $loaders
+   */
+  protected $loaders;
+
+  /**
+   * The event dispatcher to notify of routes.
+   *
+   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
+   */
+  protected $dispatcher;
+
+  /**
    * Construcs the RouteBuilder using the passed MatcherDumperInterface.
    *
    * @param \Symfony\Component\Routing\Matcher\Dumper\MatcherDumperInterface $dumper
    *   The matcher dumper used to store the route information.
    * @param \Drupal\Core\Lock\LockBackendInterface $lock
    *   The lock backend.
+   * @param array $loaders
+   *   An array of \Drupal\Core\Routing\RouteLoaderInterface objects.
+   * @param \Symfony\Component\EventDispatcherEventDispatcherInterface
+   *   The event dispatcher to notify of routes.
    */
-  public function __construct(MatcherDumperInterface $dumper, LockBackendInterface $lock) {
+  public function __construct(MatcherDumperInterface $dumper, LockBackendInterface $lock, array $loaders, EventDispatcherInterface $dispatcher) {
     $this->dumper = $dumper;
     $this->lock = $lock;
+    $this->loaders = $loaders;
+    $this->dispatcher = $dispatcher;
   }
 
   /**
@@ -59,13 +85,18 @@ public function rebuild() {
 
     // We need to manually call each module so that we can know which module
     // a given item came from.
-
-    foreach (module_implements('route_info') as $module) {
-      $routes = call_user_func($module . '_route_info');
-      drupal_alter('router_info', $routes, $module);
-      $this->dumper->addRoutes($routes);
+    // @todo Use an injected Extension service rather than module_list():
+    //   http://drupal.org/node/1331486.
+    foreach (module_list() as $module) {
+      $collection = new RouteCollection();
+      foreach ($this->loaders as $loader) {
+        $collection->addCollection($loader->getRouteCollection($module));
+      }
+      $this->dispatcher->dispatch('routing.alter', new RouteBuildEvent($collection, $module));
+      $this->dumper->addRoutes($collection);
       $this->dumper->dump(array('route_set' => $module));
     }
+
     $this->lock->release('router_rebuild');
   }
 
diff --git a/core/lib/Drupal/Core/Routing/RouteLoaderInterface.php b/core/lib/Drupal/Core/Routing/RouteLoaderInterface.php
new file mode 100644
index 0000000..1ab2b42
--- /dev/null
+++ b/core/lib/Drupal/Core/Routing/RouteLoaderInterface.php
@@ -0,0 +1,25 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Routing\RouteLoaderInterface.
+ */
+
+namespace Drupal\Core\Routing;
+
+/**
+ * Interface for returning routes for a Drupal module.
+ */
+interface RouteLoaderInterface {
+
+  /**
+   * Returns routes for a given Drupal module.
+   *
+   * @param string $module
+   *   The Drupal module to load routes for.
+   *
+   * @return \Symfony\Component\Routing\RouteCollection
+   *   A RouteCollection.
+   */
+  public function getRouteCollection($module);
+}
diff --git a/core/lib/Drupal/Core/Routing/YamlRouteLoader.php b/core/lib/Drupal/Core/Routing/YamlRouteLoader.php
new file mode 100644
index 0000000..651a2e6
--- /dev/null
+++ b/core/lib/Drupal/Core/Routing/YamlRouteLoader.php
@@ -0,0 +1,40 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Routing\YamlRouteLoader.
+ */
+
+namespace Drupal\Core\Routing;
+
+use Symfony\Component\Yaml\Parser;
+use Symfony\Component\Routing\RouteCollection;
+use Symfony\Component\Routing\Route;
+
+/**
+ * Loads routes from a module's MODULE.routing.yml file.
+ */
+class YamlRouteLoader {
+
+  /**
+   * Implements Drupal\Core\Routing\RouteLoaderInterface::getRouteCollection().
+   */
+  public function getRouteCollection($module) {
+    $parser = new Parser();
+    $collection = new RouteCollection();
+    $routing_file = DRUPAL_ROOT . '/' . drupal_get_path('module', $module) . '/' . $module . '.routing.yml';
+    if (file_exists($routing_file)) {
+      $routes = $parser->parse(file_get_contents($routing_file));
+      if (!empty($routes)) {
+        foreach ($routes as $name => $route_info) {
+          $defaults = isset($route_info['defaults']) ? $route_info['defaults'] : array();
+          $requirements = isset($route_info['requirements']) ? $route_info['requirements'] : array();
+          $route = new Route($route_info['pattern'], $defaults, $requirements);
+          $collection->add($name, $route);
+        }
+      }
+    }
+    return $collection;
+  }
+
+}
diff --git a/core/modules/system/system.api.php b/core/modules/system/system.api.php
index e4c4ce7..a5a5821 100644
--- a/core/modules/system/system.api.php
+++ b/core/modules/system/system.api.php
@@ -566,51 +566,6 @@ function hook_menu_get_item_alter(&$router_item, $path, $original_map) {
 }
 
 /**
- * Defines routes in the new router system.
- *
- * A route is a Symfony Route object.  See the Symfony documentation for more
- * details on the available options.  Of specific note:
- *  - _controller: This is the PHP callable that will handle a request matching
- *              the route.
- *  - _content: This is the PHP callable that will handle the body of a request
- *              matching this route.  A default controller will provide the page
- *              rendering around it.
- *
- * Typically you will only specify one or the other of those properties.
- *
- * @deprecated
- *   This mechanism for registering routes is temporary. It will be replaced
- *   by a more robust mechanism in the near future.  It is documented here
- *   only for completeness.
- */
-function hook_route_info() {
-  $collection = new RouteCollection();
-
-  $route = new Route('router_test/test1', array(
-    '_controller' => '\Drupal\router_test\TestControllers::test1'
-  ));
-  $collection->add('router_test_1', $route);
-
-  $route = new Route('router_test/test2', array(
-    '_content' => '\Drupal\router_test\TestControllers::test2'
-  ));
-  $collection->add('router_test_2', $route);
-
-  $route = new Route('router_test/test3/{value}', array(
-    '_content' => '\Drupal\router_test\TestControllers::test3'
-  ));
-  $collection->add('router_test_3', $route);
-
-  $route = new Route('router_test/test4/{value}', array(
-    '_content' => '\Drupal\router_test\TestControllers::test4',
-    'value' => 'narf',
-  ));
-  $collection->add('router_test_4', $route);
-
-  return $collection;
-}
-
-/**
  * Define menu items and page callbacks.
  *
  * This hook enables modules to register paths in order to define how URL
diff --git a/core/modules/system/tests/modules/router_test/router_test.module b/core/modules/system/tests/modules/router_test/router_test.module
index 4da939d..b3d9bbc 100644
--- a/core/modules/system/tests/modules/router_test/router_test.module
+++ b/core/modules/system/tests/modules/router_test/router_test.module
@@ -1,34 +1 @@
 <?php
-
-use Symfony\Component\Routing\Route;
-use Symfony\Component\Routing\RouteCollection;
-
-/**
- * Implements hook_router_info().
- */
-function router_test_route_info() {
-  $collection = new RouteCollection();
-
-  $route = new Route('router_test/test1', array(
-    '_controller' => '\Drupal\router_test\TestControllers::test1'
-  ));
-  $collection->add('router_test_1', $route);
-
-  $route = new Route('router_test/test2', array(
-    '_content' => '\Drupal\router_test\TestControllers::test2'
-  ));
-  $collection->add('router_test_2', $route);
-
-  $route = new Route('router_test/test3/{value}', array(
-    '_content' => '\Drupal\router_test\TestControllers::test3'
-  ));
-  $collection->add('router_test_3', $route);
-
-  $route = new Route('router_test/test4/{value}', array(
-    '_content' => '\Drupal\router_test\TestControllers::test4',
-    'value' => 'narf',
-  ));
-  $collection->add('router_test_4', $route);
-
-  return $collection;
-}
diff --git a/core/modules/system/tests/modules/router_test/router_test.routing.yml b/core/modules/system/tests/modules/router_test/router_test.routing.yml
new file mode 100644
index 0000000..a49dd80
--- /dev/null
+++ b/core/modules/system/tests/modules/router_test/router_test.routing.yml
@@ -0,0 +1,20 @@
+router_test_1:
+  pattern: '/router_test/test1'
+  defaults:
+    _controller: '\Drupal\router_test\TestControllers::test1'
+
+router_test_2:
+  pattern: '/router_test/test2'
+  defaults:
+    _content: '\Drupal\router_test\TestControllers::test2'
+
+router_test_3:
+  pattern: '/router_test/test3/{value}'
+  defaults:
+    _content: '\Drupal\router_test\TestControllers::test3'
+
+router_test_4:
+  pattern: '/router_test/test4/{value}'
+  defaults:
+    _content: '\Drupal\router_test\TestControllers::test4'
+    value: 'narf'
diff --git a/core/update.php b/core/update.php
index 968e8f4..1ec66c4 100644
--- a/core/update.php
+++ b/core/update.php
@@ -459,7 +459,9 @@ function update_check_requirements($skip_warnings = FALSE) {
   ->addArgument(new Reference('database'));
 $container->register('router.builder', 'Drupal\Core\Routing\RouteBuilder')
   ->addArgument(new Reference('router.dumper'))
-  ->addArgument(new Reference('lock'));
+  ->addArgument(new Reference('lock'))
+  ->addArgument(array())
+  ->addArgument(new Reference('dispatcher'));
 
 // Turn error reporting back on. From now on, only fatal errors (which are
 // not passed through the error handler) will cause a message to be printed.