I can give you a few good reasons to get a new PC. Witcher 2, BF3, GW2, and if you like console shooters they are only better at 1080p with a m/kb.
I'm well aware. Diablo 3, Battlefield 3 and Skyrim are probably the games I'd most like to play on PC. I do have some arrangements where I could get a PC for cheap. Just thinking about it. I have lots of issues with PCs in general and not sure if I want to go back to having one.
That said playing Guild Wars Alpha was one of the better PC gaming experiences I've had, and the Guild Wars 2 footage is looking very good. I prefer action controls to point and click MMO style. I'm not sure how the targeting and melee works in Guild Wars 2, but it still looks fast and frantic, like an action game.