Valve spokesperson told Road to VR that they’re not promising to support stereoscopic 3D for flat games but they are looking into it.
The company further said it’s considering a system-level implementation that could display any stereoscopic 3D content, whether it’s stereoscopically rendered games, videos, or photos. Should the stereoscopic 3D feature be built, Valve told me it would “be our goal” to be able to display such content when streamed from a PC or rendered directly on the headset itself.
This was a thing for a bit in the Xbox 360 era, but disappeared as quickly as it appeared. Wasn’t there some Nvidia thing that also tried to do this on PC?
Edit: https://en.wikipedia.org/wiki/Nvidia_3D_Vision
Allowed it with any DirectX game apparently.
It is a shame 3D Vision was phased away by Nvidia. I feel like it would have a better chance of success now that many people have VR headsets and no-glasses 3D monitors are starting to appear.