There's a very good chance that PC gamers will dwindle to perhaps a gross world-wide, and they'll still be holding to the 'srsly guiz, colsoles r teh suxxorz' approach that prevails nowadays. This isn't due to the quality of the platform, but purely the profitability. The vast majority of console gamers (and I say this without verification, but still in complete confidence) don't buy their own games, they have their parents do it for them. As such, the major market is a group that have no concept of the real value of money - hence, they'll crack out the family credit card at the slightest whiff of new content. The market itself will still be alive, as we can see from sorry-ass titles like MW2 (sorry to those of you who bought it [and at release day prices at that!], but you've been had), but it'll be so bloated with money-hungry annual rehashes that the unsung heroes are going to end up forever restricted to the classification of 'indie games'. PC gaming won't die, but it's never gonna be the all-consuming dominatrix we all hate but love.
Edit: If you don't know what a gross is, you suck at life.