We have a Native Steam forum for Linux but we have forgotten about Desura! Desura Games Click the Penguin to browse Linux games Desura has a LOT more games than Steam right now... some of the same ones too. So instead of just a "Steam Powered Linux" category, how about "Native Linux Games" with Desura & Steam subforums?
We should consider GOG (Good Old Games). They have a small linux section, that might improve with encouragement.
the only difference is Desura has a client that downloads and installs the game for you. Good Ole Games just has a download and you still have to install the game yourself.
Black Judas has a game mix that "apparently" run natively in LInux: Games that run natively in Linux also, Heethen has a game mix for games that run in Wine: Games that work on Linux (Wine)