As much as I don't like the look of Windows 8, I've been considering building a better PC with gaming in mind and I might end up going with Windows 8 as the primary OS. Usually I'd just stick a Linux distro on it but unfortunately developers and users still haven't made the transition to Linux based systems yet :(
If Linux had more support from game developers, installing Windows wouldn't even be crossing my mind but unfortunately it seems to be the only option if you want to game with relative ease.
On the plus side, I've watched a few people review Windows 8 not too long ago and while they all seemed to agree that it felt strange at first, I think they all ended up liking it once they adjusted. I haven't properly used a Windows OS since XP, so it will probably be quite a jump for me, if I do take the Windows route.