Today I’ve picked up my leap motion controller and started testing it.
My experience is far from stellar so far: tracking is fairly bad, at least in my environment.

The software logged a message about compensating for an external IR source ([15:24:44] [Warning] The device has entered ‘Robust Mode’ to compensate for external sources of infrared light.) but there it is no indication of where this IR source might be.
Calibrating didn’t worked well: the matte surface of the screen is not what the device would like to use. Too bad that matte screens are way better for work use.

The device runs fairly warm to the touch and the associated software gets the Dell 6430u temperature up and the fan to run at high-speed.

I hope that the software will get better with time.
People that has not preordered it would be better holding back at the moment as far as the windows platform is concerned.