Android, Linux, is finally ruling now over iPhone
Nokia N9, MeeGo Linux, is the only phone that has been declared by some folks to be even better than iPhone in UI design, sweeping the floor with the sweep action (trying to have some iPun there)
Ubuntu with a tablet UI, but wich one?
As people mentioned: Unity sucks
and none of the others are designed for phones/tablets
Thre is a rocky road ahead
Windows 8 Metro UI...dare I say anything? better not
Windows Phone 7.5 will be replaced by Windows Phone 8 with Metro UI
Windows 9 (NT 6.3) is still using the "new" Vista driver model
I'm waiting for Windows X with virtual IO subsystem and
VM engine build in with fully integrated CPU support from Intel
before year 2020