I don't think the PC will ever die as a gaming platform simply because there are so many out there. Probably as many PCs in homes as there are consoles, going by the fact that most consoles are internet enabled and most people have the internet for their PC to begin with.
That said, I think the big thing that killed PC gaming was simply greed. You basically had a situation where with constant hardware updates, gaming companies were releasing games only with the newest hardware. PC gaming companies often didn't bother to worry about trivial things like testing hardware and ensuring that their games were compadible with all the versions of the things they said they were compadible with. This is something an angry user calling tech support and being told to "contact their hardware manufacturer" (and then being told it was a software problem if you were ever stupid enough to do it) is probably quite familiar with.
There is no doubt that PC gaming is, and always will be, superior to consoles. Mouse and Keyboard is never going to be overcome for most game generes by keypads. As it is FPS games and the like that have seen shared arenas between PC and Console users have had balance issues due to this (Shadowrun being paticularly infamous, even if they are working on the problem).
The problem of course being that a console stays "up to date" for five years, and then oftentimes sees further development of titles even when a next gen system is out there for a couple of years. In comparison I bought a new PC last year, and I'm already worried if next year (3 year cycle tops) I'll be able to play the latest games and MMORPGs. On the other hand I have no fear that I will be able to find new games for my PS-3, 360, DS, or PSP.
I feel that PC gaming could be "saved" if game developers were to pretty much pick a hardware set, and then have the willpower to stick with that general PC hardware/driver/software set for several years rather than updating constantly to a new plateau. If the game industry worked together for anything but gouging consumers this is a problem that could be easily addressed and the PC could easily become as good as the
consoles out there.
It should also be noted that when it comes to things like RTS and RPGs the PC is still king. Dragon Age: Origins has garnered some eyebrow raises with the fact that the 360 version is not going to allow for an overall strategic perspective (and this is a "WTF" moment when your looking at the spiritual successor to Baldur's Gate). I have no doubt it will be workable, but I have a feeling the PC will hands down be a superior format. For reasons related to my RL lifestyle I will be getting two versions (PC and 360) pretty close to each other and will probably be able to compare them for people pretty soon after release (unlike most users) I might very well put this up on The Escapist when I have the abillity to make a fair comparison.
It could also be noted that going by the Japanese-Origin mods and such, it seems that Japanese gamers themselves seem to think PC-based Western RPGs are superior to a lot of JRPGs. Indeed I've actually read articles years ago comparing the two from their perspective, and while very racist and put-downish, a lot grudgingly admit that JRPGs could stand to copy more from WRPGs. Back around the time of say Final Fantasy X, when I was reading some of the stuff about why neither "Final Mission" (ending the story), or the "International" version were going to make it to the US, I also remember reading translated comments on why the Japanese had yet to produce much in the way of Sandbox games, or an Oriental themed sandbox RPG on the level of Oblivion featuring pan-asian themes, as opposed to a mish-mash of ancient western themed material. The answer seemed to be that the J RPG format is "Japanese invented" pretty much and as such maintained as a matter of national pride, and adapting more western methodology would be considered a blow to many... even if the exact writer seemed to think this was foolish (while at the same time claiming they could do it better and steal the Western RPG). It also made referance to the enduring inspiration of games like "Wizardry" which Japan adopted from the US and still continued to an extent (and ultimatly lead to me running out to get "Forsaken Lands" which was one of the only Japanese Wizardry games to make it to the US).
The point of this being that all racism and such aside, I feel that with the general increase in computer gaming internationally, I think that if the format was to switch back to PC, or balance out more, you would see the Japanese game developers (who frankly shovel out most of the video gaming one way or another it seems) change formats.
This in response to points made elsewhere through the years that the console focus is in part due to Japan and the whims of their game developers. There is SOME truth to that, but then again gaming just happened to "Boom" (for economic reasons among others) when consoles happened to be pushing ahead, so that happens to be what they use. There is a bit of assumed cultural superiority behind companies like "Sony" and their success that helps fuel this, but the Japanese also produce a lot of computers (as anyone on the receiving end of the old RAM trade war can attest) so really, I think that if PC game developers (here and overseas) ever decided to get it together, I think a lot of developers would jump on board.