Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 18495)
+++ wp-includes/taxonomy.php	(working copy)
@@ -1892,6 +1892,8 @@
 		$select_this = 't.term_id';
 	else if ( 'names' == $fields )
 		$select_this = 't.name';
+	else if ( 'slugs' == $fields )
+		$select_this = 't.slug';
 	else if ( 'all_with_object_id' == $fields )
 		$select_this = 't.*, tt.*, tr.object_id';
 
@@ -1900,7 +1902,7 @@
 	if ( 'all' == $fields || 'all_with_object_id' == $fields ) {
 		$terms = array_merge($terms, $wpdb->get_results($query));
 		update_term_cache($terms);
-	} else if ( 'ids' == $fields || 'names' == $fields ) {
+	} else if ( 'ids' == $fields || 'names' == $fields || 'slugs' == $fields ) {
 		$terms = array_merge($terms, $wpdb->get_col($query));
 	} else if ( 'tt_ids' == $fields ) {
 		$terms = $wpdb->get_col("SELECT tr.term_taxonomy_id FROM $wpdb->term_relationships AS tr INNER JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tr.object_id IN ($object_ids) AND tt.taxonomy IN ($taxonomies) $orderby $order");