There is no console among those three that I will just go out and buy the minute it's out. Experience has taught me not to fall for hypes, even though Nintendo has been the least disappointing to me all these years.
I'm least likely to go and buy an XBox 360 though. The original XBox never appealed to me and most likely its successor won't either.
The Revolution is still shrouded in mystery: anything can happen. I'll wait for my cousin to buy one, then go over to his place to see what it's like.
The PS3 looks powerful and promising, but they also promised great things for the PS2, things we all know were never realized, or far too little, seeing as how the PS2 was raped by many a cheap developer and only a few titles really tried hard to pull everything out of the PS2, such as Transformers, Zone of The Enders, among others. The PS2 suffered from its own popularity, especially with EA games; they just had to also be for PS2, so they half-assed it and you ended up with a mediocre product that could've been so much more. The PS2 had only a handful franchises that were PS2 only, like Jak and Daxter, Ratchet and Clank, et cetera, but IMO they never had the power of a franchise such as Zelda or Mario.
The XBox, IMO, has always been a bit like the PS2, only more powerful. Trying to be a little bigger, a little badder, and adding competent online capabilities. It's like the PS2 in that they pretty much had the same games (except for XBox exclusives of course). To me, the XBox never really did anything new that particularly interested me. I see no reason for the XBox to radically alter its course, so it will likely remain uninteresting to me.
Okay, so that was a little long and drawn-out, but my main point is that I'll just wait and see, and if I like any of the new consoles and their games, I'll go out and buy one.