The Leap Motion Controller is one of those devices that looks cool enough to buy even if it ends getting used, at best, infrequently. Thankfully, in this case, the device is $79.99 which is reasonable enough for promising yet unproven tech (in terms of long-term viability) that you can wow your friends with. Should you have gotten a pre-order in, units will be shipping on May 13, 2013 as well as appearing on Best Buy store shelves in the US beginning May 19.
Ultimately, it all comes down to the software library, or lack thereof. Leap Motion will have its own app store called Airspace which has confirmed support: plug-ins for Autodesk, Corel's Painter apps, a music game called Dischord from Double Fine, and Cut the Rope, to name a few.
If curiosity doesn't get the best of you, we should have a review of the Leap Motion Controller at a date closer to launch. For the time being, check out this hands-on video from Max.