I keep dabbling with ubuntu linux because it is free and I dread to give MS any more money. I'm still on XP and will probably be until it is dead. Most of the linux games are FPS or RPG and not my style. Using wine to run Windows games is a mixed bag.
Things may be changing soon with the announcement that the Unity 3D game engine will support linux in the next version. Here is one article about it and there is a thread at ubuntu forums discussing it
http://linuxgamingnews.org/2012/06/18/unity4-will-have-a-native-exporter-to-gnulinux-desktop/
Windows 8 looks like another ME or Vista with touch screen icons and rumors of an Apple store model that will restrict what can be run on your PC. A few years from now we may all have tablets and PCs will be memories but in the meantime I keep looking for other ways to do things.
Linux is my main OS, but I keep a Windows install on one of my disks purely for playing games. Support for gaming on Linux is increasing exponentially these days, especially in the indie world. It's crazy. Barely a single indie title is released these days that doesn't support all three major platforms. Such a difference from just a few years ago.
However, for me it's all or nothing. I won't bother with gaming on Linux until I can play all my games on Linux, because if I have to use Windows at all, I may as well continue to use it for all my games for ease of saved game management etc.
When the day finally comes that I can do all my gaming on Linux, Windows will be gone forever. :)
I played around with Linux a long time ago ... Mainly to get some quick unix exposure.
I was really impressed with how much more efficient Linux is on the same hardware than windows.
The only thing really that will get me off XP is 04/14. I'll probably opt for Win7 on any desktops.
Win7 is probably the next 98/XP and Win8 is probably the next ME/Vista.