Index: wp-includes/media.php
===================================================================
--- wp-includes/media.php	(revision 23389)
+++ wp-includes/media.php	(working copy)
@@ -763,9 +763,6 @@
 				text-align: center;
 				width: {$itemwidth}%;
 			}
-			#{$selector} img {
-				border: 2px solid #cfcfcf;
-			}
 			#{$selector} .gallery-caption {
 				margin-left: 0;
 			}
@@ -777,12 +774,20 @@
 
 	$i = 0;
 	foreach ( $attachments as $id => $attachment ) {
-		$link = isset($attr['link']) && 'file' == $attr['link'] ? wp_get_attachment_link($id, $size, false, false) : wp_get_attachment_link($id, $size, true, false);
+		$image_output = '';
+		if ( ! empty( $attr['link'] ) && 'file' === $attr['link'] ) {
+			$image_output = wp_get_attachment_link( $id, $size, false, false );
+		} elseif ( ! empty( $attr['link'] ) && 'none' === $attr['link'] ) {
+			$image_output = wp_get_attachment_image( $id, $size, false );
+		}
 
+		if ( empty( $image_output ) )
+			$image_output = wp_get_attachment_link( $id, $size, true, false );
+
 		$output .= "<{$itemtag} class='gallery-item'>";
 		$output .= "
 			<{$icontag} class='gallery-icon'>
-				$link
+				$image_output
 			</{$icontag}>";
 		if ( $captiontag && trim($attachment->post_excerpt) ) {
 			$output .= "