I dunno, without gaming on the PC you lose the mind share of many IT enthusiasts when compared to a Mac. Those enthusiasts will grow up to be the next gen of IT execs and it doesn't take much for the pendulum to start swinging the other way. The more people they influence, the more momentum is given to Apple, and thanks to the iPhone and possibly iPad, they're already winning a lot of mind share.
Its not a direct link but I still think its pretty stupid of MS to be deliberatly removing their platforms only real advantage over its biggest competitor (besides backwards compatibility).
I'd have to agree that PC gaming is one of the main things that keeps me on Windows OS. If I no longer had much in the way of PC gaming, and MMO's starting coming out with more OSX or X-Windows clients, then there's not a whole lot of reason left to stick with Windows.