Few months already that Unity3D released Unity5 and finally here it is, Unity5.1.1! And that's an awesome news for Unity evangelists!
If you have been waiting for the good time to upgrade your Unity 4.6 projects, then you should know that you can now do it!
Download Unity5.1 from the Unity 3D website, get also the patch 5.1.1, download the brand new Oculus SDK & Runtime Beta v.0.6.0.1 from the Oculus website. Uninstall your previous Oculus Runtime, reboot, install Unity5.1, the Unity5.1.1 upgrade, install the new Oculus SDK & Runtime, reboot, launch Unity5.1, go to Edit/Players and check the box 'Virtual Reality Supported'. That's it, you made it! Your main camera now does the job that OVR prefabs used to do.
Note that you don't need the OVR Assets to your project anymore. Now if you want to upgrade, make a copy of one of your project and load this copy in Unity 5.1. You should get a message saying Unity wants to upgrade your projects and broken scripts. Click ok go ahead. Delete your OVR prefabs, make sure the box 'Virtual Reality Supported' is checked. That's it! Have fun!