My friend's got an XBox 360, and I'm very tempted to get one myself. It's a damn nice machine.
But I've always had Playstations (got an original PSX for Christmas 1996, and the PS2 for my 14th birthday in 2001), and my brother's got an N64. Those are the only actual consoles I've ever owned, so naturally I'm more inclined to see what the PS3 is like.
The thing is, I'm very keen to get a 360, but I want to wait until the PS3 comes out to see which I prefer. Problem is, PS3 isn't out for ages.
From what I've seen, the PS3 is a bit overrated, and not many games developers like it. One thing is true, IMHO: if the PS3 flops, that's the end of Sony in the games market. After the Dreamcast flopped, Sega dropped off the map, and ended up just publishing games for other people. Their day was gone, the Genesis, Mega Drive I and II, Saturn, Dreamcast, it was all for nothing.
I also believe the Revolution looks like pure crap: even Nintendo say it's rubbish compared to the 360 and PS3, they're just appealing to a broader market. I think Nintendo went downhill after the N64 - all the Gamecube games, apart from Serious Sam and Resident Evil, were aimed at little kids.