“All of this work is broadly applicable to the PC platform, and it’s going to continue to expand over time. Supporting multiple platforms, multiple chipsets, controllers for different machines that are out there and even ones that aren’t out yet.”
[…] Valve’s goal with the OS is to have it compatible with traditional PCs, laptops, portable consoles and any other formats.
On this topic, it’s not about the money (getting paid off, or absorbed) for valve - they will continue their linux projects because the only goal is ensuring they have somewhere to sell games if MS went nuclear. While the immediate threat of windows store monopoly has subsided, SteamOS as a whole is a contingency plan over everything else, since the beginning.