Valve has confirmed that not only are they looking into the possibility of building gaming hardware for the living room (a.k.a a console), they are apparently interested in the idea of building a mobile gaming device using an open hardware solution.
As to what platform this possible mobile gaming device would run on is anybody's guess. While the closed living space of iOS doesn't support this sort of thing, Android and Windows are both possible options as well as the something that they create themselves.
“We’re looking hard at both the living-room space and the mobile space to try to see if we can create open hardware platforms that the industry can use so we can get out of proprietary traps that we’re headed in both of those,” - Gabe Newell, Valve Co-Founder.
Discussing the idea during a podcast with Seven Day Cooldown, Mr. Newell went on to talk about the hardware ideas to a degree, stating that it would be involving “barely out-there hardware design”, meaning both the living-room and mobile devices would be rather unique in design.
The best possible options however are Android or something they develop themselves. This is further supported by the fact that Newell is a strong and vocal opponent of closed platforms. It will be interesting to see what comes from Valve hardware-wise, if anything.