I've updated the MW UI demo site
(
http://mwui.wmflabs.org/wiki/Main_Page) and enabled
$wgUseMediaWikiUIEverywhere = true; (the global used by Jon's blanket MW
UI change).
Basically, we want to test this version for a while, then make it the
only version. So please click around on
http://mwui.wmflabs.org/wiki/Main_Page (e.g. try editing
http://mwui.wmflabs.org/wiki/Lorem_ipsum, among many other possibilities).
Thanks,
Matt Flaschen