At this point there is very little reason to buy a 360. There is a good chance the price will go down when PS3 is released, and if nothing else they will be readily available and maybe have changed manufacturing practices to reduce the occurence of slowdowns. In the meanwhile, they are still releasing plenty of Xbox games and the PC has a few gems, too.
Also, its unlikely that the current "console war" is going to drive people to make PC games. Exactly the opposite. PC games are a largely western industry, and virtually unheard of in Japan (excluding adult titles, those sick bastards). But once Microsoft jumped on board, they could use their tradition ties to PC developers to lure them into making Xbox games or co-releases much easier then Sony. Thats why you saw so many games that being codeveloped for the two systems. And Microsoft has something of an incentive to discourage PC gaming, since they get more money through their X-box. And all console manufacturers are trying to lure developers to their camp with minimal barriers to publishing.
The best thing for PC gaming would be Microsoft getting out of the console industry and one giant dominating, preferably Nintendo who gets along lousy with third party developers anyways. The winner would probably crank up the console fees or find other ways to make it more costly for developers to create games on their platforms. This would encourage more developers to support the PC, which doesn't have the same barriers to releasing games on it as consoles do. I think gamers go where the games are, and if thats the PC, there they'll be.
I think the industry is ready for some sort of shake up. As graphical standards rise, the cost of developing games is skyrocketing. That means no one is taking any risks, and a lot of companies are collapsing under the pressure of needing to sell several hundred thousands of copies. I suspect we'll see a lot of developers give up trying to keep up with the graphics race, and focus instead on new and innovative gameplay. Hopefully, it will work. Sort of like My Big Fat Greek Wedding succeeding, dispite sitcom quality lighting and backdrops.