That's a really good question. V2 was in beta until early October, and many people prefer to wait until APIs, UX guidelines, and resources are fairly settled before building -- while those who had an eye on releasing alongside V2 were working on their projects through the summer and ready to roll at any time.
As for the V1 apps, many of them have fairly simple interaction models that don't require V2 APIs (like Bone) in order to work -- though they still reap the rewards of better tracking. PolyDrop and Jumping Line are good examples of minimalist games that rely on simple gameplay mechanics.
All that being said, you're right to point out that there isn't much new content on the App Store. But that will be changing soon! Right now, we have a global 3D Jam taking place with teams of developers competing to build the most amazing apps they can muster for $75k in cash and prizes. VR games, rhythm games, spellcasting games, racing games, puzzles, educational experiences, you name it.
You can actually watch some of the projects in progress on our itch.io site (http://itch.io/jam/leapmotion3djam) or by watching the #3DJam hashtag on Twitter. There are also a lot of devs who prefer to keep their projects under wraps until the Big Reveal.
If you like, you can watch us play some early builds next week, when we're hosting a Let's Play session. The exact time will be confirmed this weekend 
