Thanks, great post! My point though was not some much the demise of PC gaming per se, but its consolization. There is significant cost involved in making a game that plays to the PC's strengths. Even adding such features as leaning and prone require a fair amount of programming time. In comparison, adding such features as mouse and keyboard support, text chat, and screen resizing was comparatively cheap, as most of the work can be reused from game to game. Thus the future seems to be a cheapo console port because companies like IW can reap 80% - 90% of the sales for 10% of the cost.
Games like The Sims and World of Warcraft are pretty safe because they have secure cash streams; the developers and publishers get to make money selling additional content. Developers and publishers are now doing the same to shooters, as witnessed by COD: MW2 where all content is controlled and must be purchased from them. This allows the developer to increase demand for his own downloadable content and also to kill the game when his next product comes out. When MW3 is near release, IW will release no additional map packs and may also shut down the servers for MW2 in favor of MW3. Thus your $60 investment becomes worthless, unless you want to replay the very short and linear (but probably excellent) single player campaign.
Good sales of MW2 on the PC are actually improving the odds of getting future games on PC - but only with such maps, features, and MP as is suitable for consoles. Also, in multiplayer the aiming has to be dumbed down considerably due to the lag of P2P, negating most of the value of the mouse. Thus your $1,000 high end PC becomes a $300 XBox 360 with keyboard and mouse. Under those circumstances I expect PC gaming to wither because purchasing the kind of power it takes to play these games won't make sense when a much cheaper console will give exactly the same experience. I expect the ports will continue because they cost next to nothing, there just won't be much reason to purchase them.