I am a huge fan of Unity and I absolutely love how seamless they have made the process of developing in their engine for virtual reality through the Oculus platform. They see the future, they agree with it, and they are building products to take the market there.
A great target for new VR developers is Gear VR, the mobile implementation of Oculus for Samsung. Developer kits (cleverly called the Innovator Edition) are 99$.
Most exciting, because many developers are familiar with Unity and mobile frameworks already, and because of the mass market potential of mobile VR through Oculus and Samsung, many developers will already start with skills needed to devleop for the medium, and there is potential ROI if Gear VR takes off.
A great Oculus blog post found here touches on more technical details. I highly recommend anyone considering developing for this medium to give Gear VR a long hard look as a target for initial products.