Interesting...it's good to see people are coming up with new physical interfaces to make digital technology more expressive. The website says it can do microtonal scales - very cool.
Looks like you could poke your eye out with the mouthpiece if you're not careful, though.
It's cool and all, but if the Chapman Stick (which expensive as it is, is cheaper than an Eigenharp) never really took off, I don't see this being a huge hit either.