[rlpb]

Can you be more specific? We may be talking about two different things. The Ubuntu phone requires apps specifically written for the UI (though I think things written against Qt's mobile APIs can be made fairly easily). The Ubuntu phone will not run your average X app. I'm not aware of the Ubuntu tablet proposed to be any different.

My understanding is that apps will indeed seamlessly switch between the two modes - but only where they have specifically been adapted to do so. Apps not adapted will not run. Or am I mistaken?

[gnufx]

Afraid I don't know any more than what they've written and that you can see in things like https://www.youtube.com/watch?v=fiEkCaA_P7c (I didn't interpret a desktop experience as necessarily meaning X.)