However, it does not look like the hologram is actually projected into the air yet! The video makes it difficult to see just what is happening, but I keep seeing vertical lines with differing light levels on either side, indicating a glass prism of some kind being used as a projection surface. If you watch the video of the pretty young "assistant" on their website, notice that she materializes in the same location and "disintegrates" within a rectangular boundary; and in the shots from the reverse angle one can see the reflection of the camera operator --- the "assistant" is projected into a glass prism, like most holograms.

I had imagined using a modified light-pen as an interface; but it appears that the computer's ability to track finger-movements is quite adequate.

Projecting the globe into the air would have allowed the controller to zoom in and out almost indefinitely while an audience watches from any number of angles. But I suppose a projection into an appropriately large prism would be almost as rewarding, and would not diminish the tool's effectiveness.