Steam is coming to Ubuntu and it's bringing Left 4 Dead 2 with it.
For years, Linux users looking to do a little gaming have been forced to resort to stop-gap measures like Wine, the popular Windows emulator. Of course, emulators come with a whole mess of bugs, quirks and compatibility issues, and considering that modern PC games aren't exactly the stablest of programs to begin with, frustration tends to be the rule rather than the exception. Enter Valve and project "Steam'd Penguins."
A dedicated development team at Valve has been working on a fully-featured version of the Steam client for Ubuntu 12.04 since 2011. The team already has Left 4 Dead 2 running natively under the popular Linux distribution, and they're currently working on improving the game's performance so it can launch alongside the client. Once that's done, the team is going to start porting additional Valve titles and, should the project turn out successful, look into supporting other Linux distros.
Overall, good news for Linux users, though it remains to be seen if the OS has enough interested gamers to make the venture profitable for Valve.
Source: Valve Linux Blog