silicon on 24 February 2011
In terms of FPS games, it's as much the game as the social interactions that fuels sales.
One of the reasons some people may continue to buy the new versions of the COD franchise is because of Status. When you buy the new game, you signal to everyone on your friends list that you can buy the new game, and you're going to have new achievements, and whatever other psycological benefits one can gain from buying the new version. There will always be that core group that buy it for additional achievements or want an updated experience. Once some players move the rest follow.
If FPS manage to somehow crash, I would say MMOs or games like Farmville will replace them. Games with various social interactions and lots of rewards.
