Wine is shit for games anyway, too much hassle and performance is not the best. There is wrapper called eon, developed by some company who is porting windows games. At first it was utter garbage. They ported Witcher 2 using it and game was completely unplayable, four times lower fps (10-20 on any PC) and bunch of crashes, many couldn't even start the game.
Linux users tend to be pretentious assholes and hate proprietary software, especially wrappers. Backslash was brutal, most companies would pack the bags and show middle finger to tiny Linux community. However these guys apologized and went to work. Many patches after, Witcher 2 works fine with 10% lower fps than Windows version.
Many games were ported afterwards using eon, there were input related problems and occasional freezes in some games. Their latest port was especially hard task to deal with, infamous unoptimized game called ARMA 3. Linux users were prepared for failure, considering how demanding game on Windows is. Result is something else, same average fps as on Windows (max fps is often lesser on linux but min fps tend to be much higher). Some of eon games have even better fps than Windows games. That is exceptional result because they are using wrapper. If Valve means serious with SteamOS, they'll give even more benefits to developers so they pay eon to port rest of games in Steam library.
New games can use Vulkan, but we'll see how developers will react to it. Currently they only talk about DX12. EA, Ubisoft and Activision don't seem to be interested in Linux at all but that will change if they see Valve making money with it.
Valve's Dota 2 on Source 2 engine works considerably faster on OpenGL than either DX API. At end of the year they'll develop Vulkan API which should give even better fps. It isn't matter can gaming experience be good or better on Linux than it is on Windows, It is just about money taking Microsoft does every time they feel threatened,
