http://store.steampowered.com/livingroom/SteamOS/
http://arstechnica.com/gaming/2013/09/valve-announces-linux-based-steamos-as-basis-for-living-room-gaming/
Valve Software's SteamOS was announced today and here is a summary:
"Why a new OS? Valve says that with SteamOS, the company has "achieved
significant performance increases in graphics processing, and we’re now
targeting audio performance and reductions in input latency at the operating
system level."
"The Linux-based platform will also be freely licensable to hardware
manufacturers, allowing a wide number of "Steam Box" living room PCs to
germinate. Newell has previously called Windows 8 a "catastrophe" for the
gaming market, so it's not at all surprising that his company decided to move
forward with a more open option under its direct control."
This also makes you wonder if they are going to license their improvements
under a Free Software compatible license and release upstream to the Debian
and Ubuntu repositories.