Google's Cardboard team is working on Jump [1], which is a 16-camera rig with a computer vision post-processing step to create stereoscopic 360 video.

Lytro is working on Immerge [2], which is a light field camera for "cinematic VR". So in addition to stereoscopic 360, you should be able to move your head around within the volume of the sphere as well.

[1] https://www.google.com/get/cardboard/jump/

[2] https://www.lytro.com/immerge