Don't forget that consoles actually run a fraction of those resolutions. I believe COD4 is actually rendered at 1064x600 or something along those lines, which is about 1/4th the resolution of 1920x1200.
Breaking news: current HD consoles are two generations behind in video performance and can't compete with computers built at the same price point. Update at 11.
Consoles are very limited with memory. Both the 360 and PS3 have 512MB of usable memory for running the machine, doing everything within the game, storing textures, etc. The memory architectures are different, but the bottom line is that memory is a hard constraint that will keep them from looking even close to as good as PCs with mid range hardware.
A PC builder right now can buy memory for $10/gigabyte for the main system, and he could buy a 512MB Geforce 8800GT (several times more powerful than either the 360 or PS3's video rendering) for about $160.
The PS3 has approximately a Geforce 7600 in it, right?
