Index: wp-admin/js/common.dev.js
===================================================================
--- wp-admin/js/common.dev.js	(revision 20966)
+++ wp-admin/js/common.dev.js	(working copy)
@@ -306,6 +306,30 @@
 		});
 	});
 
+	// toggle "all" checkboxes when checking a checkbox in a table list
+	$('tbody .check-column :checkbox').click( function() {
+
+		var $current_table = $(this).closest('table');
+		var $check_all_checkboxes = $current_table.find('thead .check-column :checkbox, tfoot .check_column :checkbox');
+		var $all_child_checkboxes = $current_table.find('tbody .check-column :checkbox');
+
+		$check_all_checkboxes.prop('checked', function() {
+
+			var all_checkboxes_are_checked = true;
+
+			$all_child_checkboxes.each( function(){
+				if ( !$(this).prop('checked') ) {
+					all_checkboxes_are_checked = false;
+					return;
+				}
+			});
+
+			return all_checkboxes_are_checked;
+
+		});
+
+	});
+
 	$('#default-password-nag-no').click( function() {
 		setUserSetting('default_password_nag', 'hide');
 		$('div.default-password-nag').hide();