There's really only a couple of things keeping PC games alive as a viable market. MMOGs, and the upgradability and sheer power of the PC platform as compared to consoles.
The biggest draws of the X Box? Comes with everything you have to buy extra with a PS2, has a hard drive for saving information instead of plug-in chips, and it's upgradeable. Why? Because it's based on a PC.
As long as companies can put their showiest and most graphically intense game versions on a PC as advertising to draw console gamers, and as long as a MMOG community exists, PC games are safe. If you doubt a game company would ever put economics ahead of customers, just remember EA.