has anyone seen this i cant believe it would work

You'd be amazed what engineers can do using computer technology to control stuff. Getting something to stay upright in an unstable position is a class project at my university. It probably works on the same principles as the segue. And, they're not planning on this going very fast: 20 mph top speed. Crashing on it would be no worse than crashing on a bicycle (which can still get ugly). I think its legit, or could be if you had someone with the know how and the passion for it.
I have talked to this guy downtown, its a pretty cool toy. top speed is about 15 mph and the batterey lasts about 35 minutes... he is working on a better batt pack
Speaking as a 25 yr career gizmo designer and programmer, I can say that it's actually trivial to do. The truly amazing thing here is getting the funding to build it - probably a rich playboy or something in the background!

One strategy would be to keep the seat level. Pick from a variety of methods to sense the seat position and subtly and smoothly and rapidly alter the speed of the wheel to overtake or lag the seat so that the seat stays in the same position. It would be able to sit there with nobody on it. Computer control can be amazingly fast. Instant, for practical purposes.