"Gabe Newell has responded to an email asking if Steam for Linux will be released this year with the simple answer 'Yes.' [0] That means at some point in the next 7 months anyone running Linux will be able to download Steam and start playing a number of games, including at least one Valve title (most likely Left 4 Dead 2). After that the emphasis will be on game developers to start porting their Steam games over to Linux. 2012 could be a great year for gaming on Linux. The news follows the revelation in April [1] that Valve was indeed working on a Linux port of its digital games service. At the time though, and as with all Valve software, we had no idea when it would get released."

[0]: http://www.geek.com/articles/games/steam-for-linux-will-launch-in-2012-2012065/
[1]: games.slashdot.org/story/12/04/25/1721203/valves-steam-games-coming-to-linux
[SOURCE]: http://linux.slashdot.org/