@danielwd @FallenOneX Carmack got involved with the Occulus guys while he was researching VR as a side project. They hit it off and saw the upcoming Doom 3 BFG release as a good chance to showcase the tech with a well-known title. If I was to take a guess, I would say that the amount of work involved proved more than expected and Occulus decided that releasing the kit was more important than waiting for D3. Probably the right decision.

@FallenOneX This is almost certainly an id Software/Bethesda fail, rather than a fail on the part of the Occulus guys.