PC gaming as we used to know it isn't dying. It's dead. What is classified as "PC gaming" now is just MMORPGs and flash games. There is no such thing as a PC-targeted first person shooter anymore.
I kind of disagree, but agree in other parts.
When I browse through a PC gaming mag, I see nothing but Shooters, Strategy/Wargames, MMORPGs, and the like.
What's totally missing are non-streamlined games and rather innovative games.
Few Adventures, no Jump & Run, no games like Little Big Planet, nothing colourful, nothing "just fun" ... Only shooters, strategy and wargames, in my point of view.
Just do the experiment: Browse through a PC gaming mag and sort all of the there presented games to genres ... There'll be only 5 to survive. I'm sure.
The PC platform used to be much more colourful, used to contain many more "just for fun" games, and much lesser combat-oriented games, overall. And almost no streamlined games at all, in a distant past.
Creativity is absent, PC gaming is like going to MucSwampling or to MurderKing.
I become jealous when I look "over there" at other platforms (consoles) and see what kind of non-combat-oriented games are there. Little Big Planet wouldn't be commercially developed for the Pc platform at all, because it just wouldn't sell in an environment that prefers that narrowed-down list of available gaming genres.
To me, it's like the publishers grew up their own kind of customers, too. It's like getting an animal getting accustomed to a certain diet; later, because of just being accustomed to that diet, the animal wouldn't want to eat something else.
I still believe a similar thing happened with the PC market. And with consoles likely, too.
The PC as a gaming platform is imho going down because the
variety has been narrowed down - down to a level where it becomes unhealthy for the platform (like missing Vitamines, for example).
Browser games are in my opinion the only exception to that. They provide a variety of games I otherwise wouldn't see on the PC platform.
Edit: Did I mention that 4-pages ad by Microsoft for xbox-Halo-Wars in the PC gaming mag "Gamestar" ? Happened this month.