What I'd really like to see is something like the Oculus Touch controllers:
They are awesome. They have the gamepad form factor and can be used like a regular gamepad. But then they are also great in VR, because they just mold to your hands.
Also fun is that you can let go of the controllers by stretching out your hands and using the ring. And you can wave your hands in a virtual space.
Yea, the Touch controllers are already very good, I just think that a system to keep them in your palms without needing to grip them at all (like the planned "Valva Knuckle" controllers seem to get) would be another great update to them and further extend the range of gameplay/immersion they can provide. Hopefully Sony can combine all that into their next gen motion controllers for VR.