I installed it on my localhost sandbox, and it works without a hitch (Win8, running sites on IIS, latest Chrome browser). I dig the new look!
Frankly though, I was underwhelmed when I ran it on my iPhone. If you're updating the back end UI, it's time to work out a mobile stylesheet. Can I volunteer to help with that? I really don't think it would take a severe amount of effort to get the back end mobile-tuned (once somebody wireframes all of the screens, anyway).
Excellent effort -- thanks to all of the contributors on this!
Just when I thought I couldn't love WordPress more, the contributors went and awesome-ified MP6 for mobile winning. I can't begin to describe the ease with which I will henceforth be able to tell my clients they can update their site via mobile without a hitch.
Thanks a million to the contributors for banging this out so deftly. Please let me know where I can send cookies.