This is quite a thing. Does anyone know how they're achieving the 10gbps data rate? I'm wondering if they're doing something like vortex beam forming... http://www.gizmag.com/twisted-light-beam-data-transmission-v... and http://www.sciencedirect.com/science/article/pii/S0030401809... (Although this article is about using a physical fiber).
Having worked on the pointing/tracking/acquisition side of this problem that's the part that's truly impressive to me. Sub-microradian pointing is not trivial. Their "red beam following green beam" shots in the video must be included for a bit of a laugh...
[1] http://www.ndia.org/Divisions/Divisions/ScienceAndEngineerin...