In my experience, Google's approach, and those "cloud" computing fads are a return to the mainframe, slow as hell, incredible lagging experience, standardized interface of years past. Google is evil...
Even under perfect coverage, the moment you hit highway speeds your 3G speeds will drop like a rock. Even if there's enough speed, the LAG gets much worse than what it already is. You count lag in seconds in a car. That's cloud computing for you, even in downtown, as you zoom past cell towers in an overpass at 75mph.
I hated mainframes. I hated their interface and there was nothing I could do about it. I loved my 8 bit Apple/Sinclair at home because it was PERSONAL. I could tweak whatever the hell I want . And it felt faster and looked cooler than any amber terminal I ever used.
IMHO the only guys excited about mainframes are the IT types responsible for playing with it or developing for it. Anything custom you want, you have to request them to code, because they didn't foresee that. But hey the prospect of playing this huge mainframe/Google network of computers and it's OS is enticing. But not for me, as I can't code (anymore).
End users? They have no idea what's up for them if they're not careful: DUMB TERMINALS. How's that exciting?
Just my .2c