I remember seeing YikeBike on here about half a year ago (http://news.ycombinator.com/item?id=810787) to fairly mixed thoughts, particularly in terms of style (kinda uncool) and safety. Honestly I wouldn't want to drive through any part of Manhattan on it; hitting any sort of pothole or crack in the street would seem to be painful.
It'd be illegal on the road too - it needs license plates, lights and a tax disc, and the rider should have a motorcycle license and a helmet. An electrically-assisted bicycle is still a bicycle, but take the pedals off and add a throttle and it becomes a motorcycle. I believe the laws are similar in the rest of the EU, although some states have a 'light motorcycle' vehicle class which would ease (though not entirely obviate) homologation as a motor vehicle.
I expect the machine to fall into the same regulatory and marketing abyss as the Segway - too expensive, not enough speed or range and illegal in most jurisdictions.
I don't see what's wrong with pedalling, especially over the meagre 9-10km range advertised for the yikebike. If you're not fit enough to comfortably ride three miles each way to work, you really need the exercise.
