Index: wp-content/themes/twentytwelve/functions.php
===================================================================
--- wp-content/themes/twentytwelve/functions.php	(revision 21522)
+++ wp-content/themes/twentytwelve/functions.php	(working copy)
@@ -314,9 +314,9 @@
 	);
 
 	// Translators: 1 is category, 2 is tag, 3 is the date and 4 is the author's name.
-	if ( '' != $tag_list ) {
+	if ( $tag_list ) {
 		$utility_text = __( 'This entry was posted in %1$s and tagged %2$s on %3$s by %4$s.', 'twentytwelve' );
-	} elseif ( ! empty( $categories_list ) && twentytwelve_is_categorized_site() ) {
+	} elseif ( $categories_list && twentytwelve_is_categorized_site() ) {
 		$utility_text = __( 'This entry was posted in %1$s on %3$s by %4$s.', 'twentytwelve' );
 	} else {
 		$utility_text = __( 'This entry was posted on %3$s by %4$s.', 'twentytwelve' );
@@ -337,16 +337,15 @@
  * Returns true if a blog has more than one category.
  *
  * @since Twenty Twelve 1.0
+ * 
+ * @return bool Whether blog has more than one category
  */
 function twentytwelve_is_categorized_site() {
-	$non_empty_categories = get_categories( array(
+	$non_empty_categories = wp_count_terms( 'category', array(
 		'hide_empty' => 1,
 	) );
 
-	if ( is_wp_error( $non_empty_categories ) || empty( $non_empty_categories ) || count( $non_empty_categories ) < 1 )
-		return false;
-
-	return true;
+	return ( ! is_wp_error( $non_empty_categories ) && $non_empty_categories > 1 );
 }
 endif;