add_action('wp_dashboard_setup', 'my_dashboard_widgets');
function my_dashboard_widgets() {
     global $wp_meta_boxes;
     // remove unnecessary widgets
     // var_dump( $wp_meta_boxes['dashboard'] ); // use to get all the widget IDs
     unset(
          $wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins'],
          $wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary'],
          $wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']
     );
     // add a custom dashboard widget
     wp_add_dashboard_widget( 'dashboard_custom_feed', 'News from 10up', 'dashboard_custom_feed_output' ); //add new RSS feed output
}
function dashboard_custom_feed_output() {
     echo '<div class="rss-widget">';
     wp_widget_rss_output(array(
          'url' => 'http://www.get10up.com/feed',
          'title' => 'What\'s up at 10up',
          'items' => 2,
          'show_summary' => 1,
          'show_author' => 0,
          'show_date' => 1,
     ));
     echo "</div>";
}

http://www.smashingmagazine.com/2011/05/10/new-wordpress-power-tips-for-template-developers-and-consultants/

If you build WordPress websites for clients, then the number of WordPress news feeds loaded by default in the dashboard might be an annoyance. If you’re clever, you might just inject some of your own client’s news.

Dashboard News Feeds

PHP