Not that it's anything new or radically different, but the choice of a physical keyboard is a nice difference in form factor between the iPhone and Android. It was certainly a deciding factor for me. Still, it seems like the reason for the typical form factor's success is that it just makes sense. Wide enough screen for occasional video watching, but not too large so that it's awkward to hold. Buttons down the bottom, because they're out of the way, but still easy to hit. Notification bar up top to show what's new, because that's where menu bars typically are.
Do you have any particular ideas in mind when you're discussing wildly different?
I am intrigued by the idea of having something modular. I think plugging a phone into a case to get a notebook or tablet is pretty cool. I guess I want a block of cpu/memory/storage to be my portable home (kinda like some people used their iPods for) that had docks and cases to become something else. Probably a pipe dream, but it would be interesting.
Or maybe something designed with bluetooth as a known instead of an option.
Do you have any particular ideas in mind when you're discussing wildly different?