I'd rather a linux sub sys for windows -- gamers on linux would flock to it, wine sux. There's some nice windows apps, and niche things built only on windows -- but I've staying on Ubuntu most likely.
Steam has so many games for Linux now, and a lot of that is due to Wine having advanced to the point where porting to Linux has become relatively trivial. Wine basically has allowed me to go years between reboots into Windows on my previous laptop; and I expect once I get Linux installed on my new laptop, I won't need to reboot into Windows again for another year or two or three. My favorite games are all working on Linux, mostly because of Wine (I don't run them explicitly under Wine, but a lot of the ports on Steam are using Wine behind the scenes).