Linux requirements appear for some Steam games
Some game pages have been updated on Steam by Valve to include Linux system requirements, perhaps hinting that an official Steam for Linux launch is approaching.
Joystiq reports that Steam have added over 30 standard and Greenlight games that run on Linux.
Valve founder Gabe Newell recently commented that Valve is looking into ways PC's can work in living rooms due to Big Picture mode receiving bigger than anticipated interest. A Steam box system would obviously require an OS, with Linux possibly being an ideal option.