Graphics arnt that good?
Gears of War on 360 (click on the HD one on the right);
http://uk.media.xbox360.ign.com/media/747/747891/vid_1736410.html
Compare this to the 'killer app' thats been released with the PS3, which is supposed to show the PS3 off, Resistance Fall of Man;
http://uk.media.ps3.ign.com/media/748/748483/vid_1740408.html
Most people thus far from the Japanese launch have been dissapointed that the PS3 isnt what it was cracked up to be. The Xbox has almost 60 games available, and top ones at that.
You'd be much better off getting the 360. The technical advancements of the PS3 are only marginal, and certainly dont tranfer themselves to the games at the moment. People can say 'yeah but these are launch titles' which yes, they are, but Fall of Man was supposed to be a 'killer app' and frankly it looks rubbish. Oh, and Tony Hawks on the PS3 is reported to slow down to 15 fps with graphics which, again, dont match the 360 version. I used to be a Sony fanboy and owned the PS2 so I'm not biased!
....and, Sony are now shying away from the March release date and are refusing to stand by it, meaning it might get even further delayed in the UK. Add that to the £450 price tag for the basic unit, its simply not worth the extra money.
Oh, and for those that say the 360 is a year behind - this is not the case. The system itself was designed and finished months and months ago. There was a delay due to problems with the supply of the 'blu ray' diode, so realistically the PS3 has only been in development 6 months longer than the 360 - Sony just couldnt build the things.