Index: wp-admin/includes/upgrade.php
===================================================================
--- wp-admin/includes/upgrade.php	(revision 13011)
+++ wp-admin/includes/upgrade.php	(working copy)
@@ -258,6 +258,15 @@
 								'post_content_filtered' => ''
 								));
 
+	// Setup default widgets for default theme.
+	update_option( 'widget_search', array ( 2 => array ( ), 3 => array ( 'title' => '', ), '_multiwidget' => 1 ) );
+	update_option( 'widget_recent-posts', array ( 2 => array ( ), 3 => array ( 'title' => '', 'number' => 5, ), '_multiwidget' => 1 ) );
+	update_option( 'widget_recent-comments', array ( 2 => array ( ), 3 => array ( 'title' => '', 'number' => 5, ), '_multiwidget' => 1 ) );
+	update_option( 'widget_archives', array ( 2 => array ( ), 3 => array ( 'title' => '', 'count' => 0, 'dropdown' => 0, ), '_multiwidget' => 1 ) );
+	update_option( 'widget_categories', array ( 2 => array ( ), 3 => array ( 'title' => '', 'count' => 0, 'hierarchical' => 0, 'dropdown' => 0, ), '_multiwidget' => 1 ) );
+	update_option( 'widget_meta', array ( 2 => array ( ), 3 => array ( 'title' => '', ), '_multiwidget' => 1 ) );
+	update_option( 'sidebars_widgets', array ( 'wp_inactive_widgets' => array ( ), 'primary-widget-area' => array ( 0 => 'search-3', 1 => 'recent-posts-3', 2 => 'recent-comments-3', 3 => 'archives-3', 4 => 'categories-3', 5 => 'meta-3', ), 'secondary-widget-area' => array ( ), 'first-footer-widget-area' => array ( ), 'second-footer-widget-area' => array ( ), 'third-footer-widget-area' => array ( ), 'fourth-footer-widget-area' => array ( ), 'array_version' => 3 ) );
+
 	if ( is_multisite() ) {
 		// Flush rules to pick up the new page.
 		$wp_rewrite->init();