One app, Touchless, allows you to use the Leap Motion Controller to control Windows or Mac OS X directly. It also works with multifinger gestures, but the 3D gestural language isn't as easy to use as simply reaching for a touch screen. Seen here with a Dell XPS 18.
A closer peek at the nicely laid-out Airspace Store, which already has around 75 apps. A good handful run on both Mac and Windows, but some are Mac/Windows only. Categories include Education, Games, and Productivity.
Will the Leap Motion Controller ever replace your touch pad or mouse? No, not right now. But could it be a useful accessory? Well, that depends on whether you think you'd use apps with motion control. You probably already know the answer.
Playing Dropchord, a game that uses a finger from each hand in a series of arcade-like musical challenges. Games like this show how well the Leap Motion can be used for precision controls. Google Earth also works to impressive effect.