Index: wp-includes/category-template.php
===================================================================
--- wp-includes/category-template.php	(revision 6669)
+++ wp-includes/category-template.php	(working copy)
@@ -373,6 +373,12 @@
 
 	if ( 'DESC' == $order )
 		$counts = array_reverse( $counts, true );
+	elseif ( 'RAND' == $order ) {
+		$keys = array_rand( $counts, count($counts) );
+		foreach ( $keys as $key )
+			$temp[$key] = $counts[$key];
+		$counts = $temp;
+	}
 
 	$a = array();