I had a quick go on one of them. Really nice bike with a high price to match, something over £1000. Its a direct drive hub motor. The battery is 24v 10ah nimh and sits in the frame.
Totally unlike any other electric bike I've ridden. Completley silent, no throttle, the pedelec system is so smooth it didn't feel electric in any way. It just felt like I was a really strong cyclist. very nice looking aswell. not really a bike for speedfreaks though, I don't think it goes very fast.