Valve has stated that their Steambox ships with X, which indeed makes sense for the short term - it's a gaming-focused system, and so far X still has the best driver support, as the proprietary GPU drivers of Nvidia & AMD only support X for now. But in the long term, once we get good EGL drivers, they will want to move on to a modern graphics system, because of all the benefits - not only performance, but also tear-free frames, etc. Then it'll be a choice between Mir + Unity, and be compatible with Ubuntu; or Wayland + almost any other DE, and be compatible with Tizen + almost all other Linux distros.
No announcement yet.
Valve's Gabe Newell Talks Up Linux For Gaming