Title value not populated in node edit form

Hi, The title value is not set in the hook_form. Is this by design or a bug? (I would think bug) To fix add the default value (line 115 to 130):

/**
 * Implementation of hook_form().
 */
function microblog_form($node, &$form_state) {
  $type = node_type_get_type($node);
  
  $form['title'] = array(
    '#type' => 'textfield',
    '#title' => check_plain($type->title_label),
    '#required' => TRUE,
    '#maxlength' => 255,
    '#default_value' => check_plain($node->title),
  );

  return $form;
}