Look at software sales of third party games on console versus PC, mainly 360 atm. Now the PS3 is going to be costing 399$ and will pass in many more people's hands. And within a year and an half, both the PS3 and 360 are going to be a lot cheaper, making countless more PC users give into the consoles' temptation and get either system, or both. It's going to be a devastating blow to have many technically equivalent games on consoles versus on PC that run far better on such inexpensive systems. Even Mark Rein claims that most every modern game is going to be tailored around console configurations because this is where the userbase will be, with graphical PC killer apps like Crysis being very few and far between.
Ultimately, that stake is irrelevant because last summer I simply desired a high-end PC to enjoy the few exclusives that Windows still offered, and perhaps a superior port or two once in a while.