Though Google's annual I/O conference takes place next week, one of its major announcements may have just been leaked ahead of time by Epic Games. The leak comes in the form of patch notes for the latest Unreal Engine 4.12 Preview 3 build, which state: "UE-30404 Need to integrate engine changes in support of AndroidVR plugin to 4.12".
The patch notes were later revised to read "Modifications to Android OnCreate delegates", removing any mention of "AndroidVR".
Exactly what AndroidVR is at this point is unclear, but it's significant because Unreal Engine 4 has not yet introduced support for Google Cardboard. It's possible that AndroidVR will act as a universal development environment for Google Cardboard, Gear VR, and any future Android-based VR hardware from Google - or, AndroidVR could be a full-fledged VR operating system in and of itself.
We'll have more once the Google I/O conference begins next week.
Hopefully Google will adopt OSVR instead of something custom