“I think mid- to long-term it’s a significant threat. I don’t carry a DS or a PSP around, but I’ve got my iPhone everywhere. So if it plays good games, I’m less likely to pick one of the others up. …I think the stars could align and it could start to eclipse those other systems in terms of unit sales.” – John Carmack
I really don’t see any gamer giving up their DS or PSP for games on the iPhone. Until there’s some sort of universal button solution that is put together by Apple and supported by third parties, I really don’t see any contest.