Index: wp-admin/includes/update-core.php
===================================================================
--- wp-admin/includes/update-core.php	(revision 19447)
+++ wp-admin/includes/update-core.php	(working copy)
@@ -465,6 +465,9 @@
 
 	// Remove maintenance file, we're done.
 	$wp_filesystem->delete($maintenance_file);
+
+	// No return yet => succesfull
+	do_action( '_core_updated_successfully' );
 }
 
 /**
@@ -526,7 +529,7 @@
  * Redirect to the About WordPress page after a successful upgrade.
  *
  * This is a temporary function for the 3.3 upgrade only and will be removed in a later version.
- * 
+ *
  * @since 3.3.0
  *
  */
@@ -534,12 +537,25 @@
 	// Only for WP version < 3.3.0
 	if ( version_compare( $GLOBALS['wp_version'], '3.3.0', '>' ) )
 		return;
-?>
+
+	// Load the updated default text localization domain for new strings
+	unload_textdomain( 'default' ); // Needed?
+	$locale = get_locale();
+	load_textdomain( 'default', WP_LANG_DIR . "/$locale.mo" );
+
+	// Show info messages, see do_core_upgrade()
+	show_message( __('WordPress updated successfully') );
+	show_message( sprintf( __('You will be redirected to the About WordPress Page, if not click <a href="%s">here</a>'), esc_url( admin_url( 'about.php?upgraded' ) ) ) );
+	echo '</div>';
+
+	?>
 <script type="text/javascript">
 window.location = '<?php echo admin_url( 'about.php?upgraded' ); ?>';
 </script>
-<?php
+	<?php
+
+	// Include admin-footer.php and exit
+	include(ABSPATH . 'wp-admin/admin-footer.php');
+	exit();
 }
-
-add_action( 'admin_footer-update-core.php', '_redirect_to_about_wordpress' );
-?>
+add_action( '_core_updated_successfully', '_redirect_to_about_wordpress' );