Valve's Dota 2 game will soon be released for Linux gamers. Dota 2 is the sequel to Defense of the Ancients and under Windows has proven to be a highly popular title, which is now being tested on Linux.
On a Dota2.com page
where they announce the game is now out of beta, they have a FAQ about Dota 2 for Linux and OS X. The answer about the game's state for the other operating systems reads, "The Mac and Linux builds are currently in testing and will be available soon."
This is great news and should be seeing this multiplayer online battle arena game coming soon to Linux.