Patrick: having support for all GSM frequencies shouldn't be too difficult, as there are already radio chips out there that do this. Not sure on how difficult it would be to also add in CDMA support, but you can bet your butt Google and whoever is going to make their phones will charge up the wazoo for this capability.
Ramyt: I'm pretty sure AT&T will jack up prices. They effectively will have no more competition in the GSM space, unless Verizon hurries it up and expands their LTE coverage. Also, my dream of the perfect future phone would be on that is implanted directly into the brain. No more of this crappy digitizer nonsense. If you want to click on something, you just think it and BAM. Porn opens in its own window. And no one would even know you were watching porn. Unless you stood up.