I think the only thing that has been dying in PC sales is sales in the brick and mortar stores. I can't remember the last time I bought a PC game in a box from a store. Steam, GOG, Origin (*shutter*), Impulse, etc have proven that PC gaming is going strong and from the looks of things is continuing to go strong.
Things like Kickstarter are showing that indie development is also strong and even long time developers are looking to community funded games, instead of publisher funded games.
I think the line between consoles and PCs will become more and more blurred, but the pc will remain the pc.