I read an article about electric assist bikes a couple of years ago. There were one or two states with funky laws that either legally forbade electric assist bikes or classified them as mopeds requiring an operator's permit. New Jersey sticks in my head as one.

Washington forbids them on sidewalks and limited access highways, plus local jurisdictions can limit their access on trails.
http://apps.leg.wa.gov/rcw/default.aspx?cite=46.61.710

...or turns off onto a park path of some kind.

Have you seen the monocycle? That challenges definitions too.

I don't know where the hell you could ride it.

irritating the hell out of a bunch of people.
If I were driving, I wouldn't want to have to deal with it. Not as a pedestrian or riding an actual bike.

Hell, a decent biker can go that fast on a regular street ten or twelve speed, and you don't have to waste the energy to recharge it, or pollute the land to get the rare earths that go into its construction.

What a waste.

That's federal law. One can always pedal faster.

Adds probably something like thirty to fifty pounds to the curb weight of the bike.

If this is the first step in the evolution of something that will go faster, great. But if not, then it is a waste.

The batteries and motors, of those that have them, are a small chunk of weight by comparison.

Now, insofar as leading to something else, yes that is a very real possibility. Velos today are bought by cyclists. Something like the Elf seems like it could have much wider appeal, be more utilitarian, less aerodynamic so not as fast, but more people in them.

Throw in more batteries, and a bigger motor, and take off to 85 KPH (53 MPH) today--although not legally on the streets.

$4k will only get you a middle of the road pedal powered bike with two wheels, so a $4k/electric trike will have to cut some corners somewhere. Looks like a deathtrap, to me.