I hope these things don't catch on here. We have enough problems with ordinary cyclists as it is without being faced with something like this.
Looks about as dangerous as the Sinclair C5. At least that was electric powered.
I dunno... they're safer in one of those than on a regular bike, by far (a flag would help, though, so truckers don't just roll right over them!

).
Problem is, with no shoulder there, they're just in the way, at the speed they're going (faster than a regular bike, but not uphill- no way!). Getting stuck in a car behind a gaggle of them like that would be a major pain.
But I'd love to have one of those... you can ride it in the rain or cold pretty comfortably, I'll bet (the enclosed ones, that is). And damn good exercise: I used to ride quite often, it's great for the ol' stamina.

And I think a cyclist, in terms of food vs. gasoline, gets more mileage for the money on a bike than a car does... I've done 90 miles, in the mountains, on a cup of coffee, some oatmeal, and an orange (ah, to be young again!

). And I had almost 30 lbs. of food and gear on the bike (I feel old just thinking about that).
If one's only concern is getting oneself and maybe a briefcase or some groceries over a short distance, dry and warm, at about 15 mph, it's a pretty cool thing. Slow, yes, but I've spent 3 hrs in my car trying to go less than 15 miles where I live...

They won't mix with motor traffic too well, but it'd be interesting to see them used more in areas where there is little or no motor traffic- like some small island communities, or in the pedestrian-mall center of small cities.
Maybe highways for veloci- whatever the hell they're called- could be built alongside existing roads, using old rail sidings or whatever. There's already a large network of dirt trails for bikes and hikers in the US made just that way...