There are already hacks out that allow you to use the Iphone on Tmobile (the only other GSM network in the US). I believe one of the hacks is going to be commercially available in the next couple weeks, and there are several free ones in the works as well.

Everything I've read says the Iphone is great, but the AT&T network is still a piece of shit. That pretty much mirrors what AJ and others I know have experienced over the past couple years. Hopefully Apple will be able to either wriggle out of the exclusivity deal with AT&T or else come out with a similar design for non-GSM networks.