The Force Is Strong

The new Star Wars trailer is out, and even though the release of the movie is two months away people are already buying tickets.  From a look at the trailer, I can see why:  Star Wars:  The Force Awakens looks pretty cool, and may well reinvigorate one of the greatest movie franchises ever.  Han Solo!  Leia!  Luke Skywalker!  Chewie!

As for me, the coolest thing in the trailer is the rolling ball robot with the unmoving head.  How do they do some of that stuff?