It says third-party in the title. Though there will be a Valve-made Steam Box, the name "Steam Box" is set to be an identifier for any machine that is portable, running Linux and coming with Steam's Big Picture Mode pre-installed. As Gabe Newell told The Verge, there will be tiers of Steam Box machines, all made by different manufacturers:
"The way we sort of think of it is sort of 'Good', 'Better', or 'Best'," Newell told The V...
Thanks for the spot, has now been fixed.