Nice update with the image api. I see how this will come in handy for diagnostic testing as we can now see if a problem is a software one or a hardware one based on not seeing something clearly. Interesting to see how it processes stereo image data. I assumed before that it was like the kinect and projected a grid of some sort. Nice to see how robust the IR cameras are at blocking out other light. I shined a powerful 3,800 lumen led flashlight at it and the tracking was unaffected and the camera couldn't even see the light at all even when pointed right at it.
I can see how this would be useful for some basic tracking using highly visible tracking dots or spheres(Like the PS Move controller). QR codes and possibly IR strobes(tested remotes with it) may be possible for sending data to the leap. It may even be useful for facial tracking, though try holding it up to your face and you may see why it may not be ideal(not to mention be a bit scared of your distorted appearance). So due to the wide angle the applications outside of object tracking in the normal range may be difficult. I'm curious to see what others come up with.
FEEDBACK
It may be useful to provide a method for the Leap Motion software to track round objects and return their coordinates much like the pen tool. A good start would be the ability to track ping pong balls. They are highly visible, cheap, easy to mount on objects, and a predictable size and shape from any angle. I think this may be more useful to me than the direct image tracking for me as it should create a XYZ coordinate more accurate and faster than tool tracking, since angle and length of the tool is not needed.
As far as feedback on tracking goes I think it is has a bit lower latency than the last version. I am however seeing that it has trouble recognizing the index finger by itself as other when I point with just my index finger the virtual middle finger moves with it.