Nothing special (Score 3, Interesting)

This kind of thing has been done for years/decades, and is used a lot in industry already. I know of many companies that are taking their CATIA or NX models, and visualizing them in VR or CAVE systems. You can even buy software which has been written to solve this problem for you ... you just buy the VR hardware, load your model in, and you can manipulate it. For example, here is a video of something that you can go and buy right now ... http://www.worldviz.com/industries/cad ... the sample video uses a stereo projector and a wand, but you could easily use Leap Motion, a full motion capture system, or whatever hardware you have.

The gestures he shows in the video are also very primitive, and did not appear very intuitive. He spins his hand in one direction, and the model rotates about a different axis. Just spinning a model around is not really designing anything, it is just a preview technique. And in some ways, using a mouse could probably be less fatiguing and more intuitive. The real holy grail is addressing the problem of creating models from scratch. And making them accurately so the designer gets what they want, and typically designers will probably want to use a keyboard so they can enter in exact dimensions. But this is not addressed in the video, but I'm sure everyone will think that is what they actually can do.

But because Elon Musk is doing this and now you are seeing it in the popular media, he must have invented it, right?

If you want to see something really cool, check out this system, the Lockheed SAIL, which was done years and years ago ...
http://www.motionanalysis.com/html/temp/lockheedHIL.html