The "Retina Display" really does seem great, but it raises a lot of questions for game developers. I can understand making apps(especially reading apps) with 4x resolution, because it'll really enhance the experience, but I don't think it'll be as big a deal for games.
The trade off is basically between 4x resolution(that you can barely see) or 4x performance/effects, or 4x battery life. I know it won't *actually* be 4x, but it'll be a large difference. These textures will use HUGE amount of memory, and the amount of GPU time it takes to draw 4x bigger textures is HUGE. It just doesn't seem worth the trade off unless you have a very simple game like solitaire.
Thoughts?