I don't think it's fair to say that it will make a big impact on the way we use cell phones. It may be fancy and cutting edge, but it's just a phone. Not to split hairs, but until we have technology that really changes the way we use cellphones, the iPhone is just a cell phone in a pretty package.
Two-way video calling, complete computer integration, better signal strength and transfer speeds: those would be revolutionary. This is just another toy to brag about at LAN parties.