There was a time, not too long ago, when the PC was king. When major newspapers were running stories about the financial burden placed on companies due to productivity lost to Doom, when the people making the games were Ferrari-driving rock stars who dated Playboy playmates, when the hottest booth on the show floor at E3 belonged to 3DFX. Consoles may have usurped the throne, but I think that the PC is poised to take it back.
First, there's the technology. The consoles that are out now are the same they've been for 5-6 years, and since they're still doing so well, the manufacturers have no real incentive to put out new hardware, so they'll stay the same for several more. The PC, though, doesn't improve generationally, it's a steady evolution, and right now, when it comes to sheer power, today's gaming PCs are essentially a full console generation ahead. And then there's the openness of the platform. Anybody who wants to make a game can make one for the PC, and they can sell it directly, if they're so inclined, or they can give it away for free, or whatever else they feel like doing. And while all three consoles distribute games digitally, and the next generation will very probably be one without physical media, they're closed ecosystems. An Xbox owner who wants to purchase and download a game has no choice but to buy it from Microsoft. A PC owner, though, has their choice of Steam and Direct2Drive and countless others, they can shop around for the best deal because there is competition, it's a free market. And then there's the online integration, it's a computer, computers and the internet go together like bread and butter. Internet is what computers do, and it's no different with online gaming.
The platform just has so many strengths and advantages over the consoles that I really do think it's poised to make one hell of a comeback.