This is a fascinating new technology with potentially significant application in the ArcGIS world. Imagine sitting at your workstation and simply using your hands and gestures in the space in front of you to move, pan, zoom, and even draw features. (for those of us without the luxury of a cintiq) Basic navigation support would be a great start, but I can see more advance features coming along fairly quickly. This could take the place of other tools with sketchy support, such as various 3d mice or puck style tools. Bonus: it's reasonably priced.
http://leapmotion.com/An SDK is available