It looks like Microsoft has really picked up quite a bit from Zumobi for their next mobile OS.
On Techcrunch they have some screenshots that make it obvious. It will be interesting to see how the UI really works and if it’s any better than the one on current Windows Mobiles. The competition on UIs in mobile is now serious and I look forward to see if Nokia/Symbian will make the leap or will stay stuck on their existing UI (that seems a bit old to me).
PS: If you don’t find anything about a UI desgin on Zumobi, you might want to see this (now old) press release.