Here is a list of missing usefull features for VR :
Spheric paint : Paint that would allow you to paint looking through VR Device, to paint the front part of the sphere and offset the sphere between paint strokes and obviously handle the distortion properly.
perspective calibration : a tool to set some informations like draw a line along a horizontal thing to automatically set the position of an element in the sphere.
Add a planar perspective input and output to the Mapconvert node to allow us to use some traditionnal tools on a part of the sphere in a traditionnal persective view.
spheric blur : add the possibility to the blur node to consider the fact that you're working on a spherical map that loops in every direction and that the radius must be distorted.
spheric glow : same as blur
spheric 2D transform : a option in 2D transform allowing us to set a center to a transformation to apply rotation position and scale to the map.
modify the split faces cubic input in the map convert node to allow us to use separated animated sources instead of consecutive frames to input the faces.
maybe think about the possibility to have some possibly calibrated overlay parameters in most of the tools to be able to work with the VR devices instead of the screen...
That would be a good base I think.
