Index: wp-includes/admin-bar.php
===================================================================
--- wp-includes/admin-bar.php	(revision 18338)
+++ wp-includes/admin-bar.php	(working copy)
@@ -442,7 +442,7 @@
 function _get_admin_bar_pref( $context, $user = 0 ) {
 	$pref = get_user_option( "show_admin_bar_{$context}", $user );
 	if ( false === $pref )
-		return 'admin' != $context || is_multisite();
+		return true;
 
 	return 'true' === $pref;
 }
Index: wp-includes/user.php
===================================================================
--- wp-includes/user.php	(revision 18338)
+++ wp-includes/user.php	(working copy)
@@ -1463,7 +1463,7 @@
 		$show_admin_bar_front = 'true';
 
 	if ( empty($show_admin_bar_admin) )
-		$show_admin_bar_admin = is_multisite() ? 'true' : 'false';
+		$show_admin_bar_admin = 'true';
 
 	$user_nicename_check = $wpdb->get_var( $wpdb->prepare("SELECT ID FROM $wpdb->users WHERE user_nicename = %s AND user_login != %s LIMIT 1" , $user_nicename, $user_login));