I think the iPod Touch is a sleeper product here. First gen was pretty much just an iPod. Apple added a speaker, then a mic and now front/rear cameras and facetime. The current $200, own outright, no contract iPod is already a feature packed video phone (y'know, from the future) with one catch: it requires wireless connectivity, something that's only going to become more ubiquitous.

All Apple needs to do is switch off video on facetime, find a way to add voip style phone numbers (like Skype et al) and then sell it as $200 phone, no plan required.