I've heard people say "wait until the 2nd generation of PS3 games come out ect." Hey guys, we've already seen Sony's 2nd generation games! We've seen MGS and Devil May Cry 4 already, and do they look better than GofW? NO! Do they even look better than Capcom's Lost Planet? NO!
... I'd still wait. None of those games are complete, and more importantly there's the direct comparison of UE3 games that has to be done still. Plus the PS3 can play blu-ray movies, so to do the equivalent with the X360 would cost... $500-$600. Whether those are even worth bothering with (I hear upscaled DVDs are near indistinguishable from proper HD movies) is another story.
Personally, I'd say I like the art style of something like White Knight more anyway, although GoW is vastly superior to any of id's games in that regard. :P