In the office (my day job is a graphics programmer) we've been kicking around some thoughts and we've come to the conclusion that unless MS do something the next generation of consoles will, if not kill out right, leave PC gaming for anything outside of MMO, RTS, TBS and 'facebook games' on life support.
Right now the PC has a Mhz and GPU advantage however is suffers from moving hardware targets and a high draw call overhead. The former makes it a pain to dev for (I've spent the last couple of weeks now working around hardware/driver bugs for our game) and the latter we have to soak up and just deal with due to the single thread Mhz advantage PCs still have.
Jump forward 3 years which is when most people seem to think the next consoles will hit/have it; consoles will have more and FASTER cores (and with the Mhz race over PCs wont be out pacing them), DX11+ GPUs as standard and the ability to construct draw lists over multiple threads thus making submission/draw faster meaning more draw calls and more stuff on screen and looking better.
Now, unless MS and the IHVs do something the PC is likely to still be restricted to single threaded draw calls (right now DX11's multi-threaded command list construction either slows things down on AMD hardware or effectively loses you a CPU core on NV hardware) and suddenly regardless of how fast your GPU is the consoles are blowing you out of the water draw call wise meaning the PC can't match a console in 'stuff on screen'.
We are already kinda at this point, the PC is only 'saved' by having the Mhz advantage but unless something changes that advantage will go away pretty quickly.
(Right now MS are blaming the IHVs and the IHVs are blaming MS and there is crazy talk about ditching DX and going 'to the metal' which I don't think anyone has really thought about as hard as they should have done. In short, it's a bit of a mess...)