Yeah, wait for the PS3. Based on what I've seen, PS3 is the real next generation.
I've played the X-Box 360 already at EB. I was playing Call of Duty 2 and I have to say that it was awesome. The game immersion was incredible. I was playing for about 10 minutes, and a buddy came from behind, grabbed me and shouted "We're leaving now!" I jumped and shouted so the whole store could hear. Scared me shitless.
But if the PS3 is anything like what the previews make it seem, it's going to kick the X-Box 360's ass. I'm talking using raw processing power to do things that it's normally not used for (especially in terms of physics processing). Like rendering water, for instance. That's always been a kind of means to judge a game's graphics. "Yeah, well how does the water look?". I've seen some crazy shit with water and waves in some of those PS3 videos that I never thought I'd see in a videogame. Waves interacting with waves, interfering with one another. Water, acting like water, looking like water. In realtime rendering. I was mesmerized.
Plus the PS3 is going to be using a 'cell' processor, which has something like 9 cores working in parallel, compared to the X-Box 360, which uses 3 separate processors. Just a lot more power and potential.