There is a diochotomy underlying this debate that Yahtzee just touched upon lightly in his last reply:
The division between a 'GAME' and 'VIRTUAL REALITY'
In a game, the gamer is conscious of the fact that he is controlling the avatar. In virtual reality the gamer IS THE AVATAR. Now granted we haven't really seen virtual reality yet, but that's exactly what the Wii is moving towards. Why go to the gym to play racquetball when you can do it in your own home. In this scenario, the gamer REALLY IS playing a VIRTUAL VERSION of racquetball, NOT a SIMULATION of racquetball.
Will VR kill normal gaming? I don't think so. People who play Star Craft are still going to play Star Craft. They're conscious that they're playing a game, and furthermore, they don't care about feeling like they're "in the action," quite the opposite in fact.
Thus I see the gaming community going in two directions. One will the the VR simulators for casual gamers that will be part of the family entertainment system (i.e. it will also provide netflix, TiVo, internet, all connected throughout the house). The hardcore games will come on consoles.
PC gaming will be die because the PC will die. Well... it won't die, it'll just be spread throughout the house. The PC gamers will just move over to consoles, and the console will probably have keyboard accessories etc, so it'll work more or less like a PC.
The consoles will really be attachments to the integrated home system, that allows one to use it for the more hardcore games.
TL;DR version: technology will integrate such the lines between hardware will blur completely, thus making the terms 'PC' and 'Console' rather obsolete.
Those are my predictions.