Was looking at that VR proof-of-concept Facebook has a monochrome display going for again.

As nice as it'd be to just have light weight glasses for a VR headset, I can't possibly fathom how they'd manage controller tracking with it. The main reason inside-out even works is because you got this chunk of plastic jutting out from the front of your face, to give the cameras some distance from your body to look around and back at you to see controllers at your sides (barely). You'd need an entirely new approach to controller tracking (Self-tracked perhaps with SoC + its own sensors? The controller battery life would be complete ass though), and I can't see them reverting back to stationary sensor solutions since it increases the barrier to entry.