Basically what psiclone said, lol...
And there is a huge possibility that Gears 3 is coming to PS3, since the contract between Epic and Microsoft was only to make the first two games, and Epic have already talked about the possibilities of multiplatform, and how it could be a good decision, which, if you ask me, is hinting that it's coming here... And yeah, you can buy the first for the PC, and the second will more than likely get ported to PC too, lol.
The new Banjo Kazooie game was a major letdown, it was waay too short, the 3D graphics were, in my opinion, terrible and too squared (Look at Banjo for gods sake !), and to be honest, Ratchet and Clank are my favourite video-game duo, so it's worth picking up Tools of Destruction, and Quest For Booty (Although the latter is only 5-6 hours max, but it isn't meant to be a fully fledged game... the first however (Tools of Destruction) can last way over 10-15 hours, and even longer if you're the type of peson that likes collecting all the weapons and such)
Call of Duty WaW is on the PS3 too anyways, so I don't see why you'd buy a new console for it... Crystal Defenders is on the PlaystationStore, so meh. Katarmari isn't TOO bad, however I think Noby Noby Boy is tons more random and you can have more fun since every level has a completely random layout with different people and things walking around, so I'd personally buy that instead (It's like £3.50 which is... $5 ?)
So what I'm basically saying, is keep your money and just spend it on more PS3 games to keep you entertained, lol. Besides, don't forget with the 360 you need to pay for the online anyways, although it might only be £40 (Uhh... $60 ?) a year, it all adds up if you think of the lifespan of the consoles, lol. If you don't know which new games to buy for the PS3, check out the PS3 thread, lol.