Will Valve contribute to the open-source driver/3D stack?
It seems as if all their efforts are focused on getting hardware manufacturers to write better blobs at this point. It would be a damn shame if all they did was support proprietary vendors and not do a single thing for the native graphics stack (Mesa, DRM, Gallium3D etc.)
I think what they actually do, is to ask the OEMs for a working driver to deliver software.
What this means, is that if OEM considers his blob driver to be "working" it will improve it instead.
For example, Intel considers its open driver to be "working", so Intel ends up improving MESA and own stack.
Its not Valve fault, its just that Nvidia and AMD suck. You just got a proof.