Forget all of the doom and gloom. The PC is doing just fine. Actually it's doing better than fine. It's breaking sales records. I think a big part of that is Steam. I bet places like Gamestop and Best Buy that pulled PC games from their shelves a few years ago "because teh PC is dying!" are feeling pretty dumb right about now.
Make good games actually designed for PC and they sell well. That's not to say consoles only have bad games, most of the exclusives are excellent, but the PC gaming market is picky and expect a certain level of quality. Give them that and the platform is just as valid as any other.
I think Gamestop and Best Buy (along with all other big box retailers) would've still come to the same result. Digital downloads have taken over. For most PC gamers now, the only reason to grab the physical copy is if you don't have the choice on Steam. But even then, the publisher would most likely have their own store to give you a digital download (Origin or Blizzard's Battle.net). Or, of course, if you have specific gift cards.
I did a lot of downloads off of Steam, but I still prefer to have a hard copy. Hell, I even print my emails.
It's estimated that there are 54 million people in the high-end PC gaming crowd. Again, PC gaming is far from dead. http://www.tomshardware.com/news/jpr-pc-gamers-numbers-pc-gaming-dead,15530.html
You know most of them just play BF3 or MW3 on them when they could do about the same thing on a console, just gotta get used to the controller. It used to be called the iron curtain