Doesn't have to be android, could be openMoko...It must be Android?
At the moment there is no software (well, @AndiTheBest wrote something, I'm hoping we can request features for it later, skinning and such), so there are a few concerns: Will there be developers that will bunch together a few AT commands and make a dataline bridge and maybe SMS to the cell towers (prototype software already working). On that dataline you can then use internet phone software. To get a real phone working... that is more work. And there are nice ecosystems waiting. Android is one of them.Windows RT is another (and I'm sure everybody... who am I kiddin'). But my bet is on:
(and we have a GTA04 in the forums, *hint, hint, nudge, nudge* )