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.
[comments] fixed edit button (source wasn't getting filled)
[editor] fixed issue with PHP execution and preview (PHP code is executed now, ACL-permitting)
[admin] added checkbox to toggle account activation status in user manager (thanks Manoj)