Twice as fast might be a bit of a stretch but I would be happy if I could shave 10-15 min off my 60-70 min commute. Most of the e-Bikes I've seen are not very efficient however, and would probably waste a lot of power due to a non-aero riding position plus added weight, higher rolling resistance etc. One of those Copenhagen wheels looks promising if they can ever make them work and have a way to by-pass the built-in speed limits. I'd be curious to try a road bike with an electric motor if it had normal drop bars.

I pass a guy on the bridge most mornings and he just coasts up the bridge without pedaling. He doesn't look much like a biker, more like someone who lost their license and was forced onto a bike.