Personally I think it's a crazy idea, because - notwithstanding what a few commentards have said - I believe not many people actually want to use their phone as a computer. A web browser, yes; an email terminal, yes; I'll concede that, but a computer? No.
Of course, Shuttleworth's view is what was behind the misguided alterations that he had his team start making to Ubuntu a few years back.
Convergence is too much like trying to make toast in a kettle. It always comes out soggy and disappointing.