Looks like the OpenVR API is now available & claims to do exactly what we want: unify VR development. It appears we should just drop the current Oculus SDK integration and implement OpenVR. That way, we get Vive & Rift support without us having to worry it. Has native support for Linux too.
License is pretty empty with no limitations or gotchas other than including the license when distributing. What do you guys think? It might be possible to just run this through some automated JNA thing to create a Java API… not sure how @jherico has been doing it (or if he is already planning on doing this with his new company & making it available for us).