Well, really its a matter of opinion, but so far its looking like, in my opinion, the PS3 will be better. The line up for the release of the PS3 I think is better then the 360, if the X-Box wanted to do well, they should've waited to release it till they got better games out for it.
Although, then again it was a pretty good idea, market wise, to hold off putting any good games out for it. Because now when the good games come out the X-Box will be at full price.
I've seen a few screens for the PS3 and they look just as good, if not better, then the X-Box games, plus the PS3 has one of my favorite game titles up for release when the consol itself is released, and thats DMC4.
I have yet to see anything that the X-Box has that has made me want to go out and buy it, so until something does I won't. As for the PS3, as soon as its out I'm picking it and DMC4 up as fast as possible.
Also in my opinion, I think that the Revolution is better then the X-Box, I mean come on, you get to play all those old school games. Now I don't know about the rest of you, but thats one huge deal, who doesn't love the original Mario?