Several major improvements: Memberlist page added (planned since about beta 2), page group support added for non-JS ACL editor (oops!), and attempting to view a page for which you lack read permissions will get you logged.
// UK lang variables
tinyMCE.addToLang('layer',{
insertlayer_desc : 'Insert new layer',
forward_desc : 'Move forward',
backward_desc : 'Move backward',
absolute_desc : 'Toggle absolute positioning',
content : 'New layer...'
});