Just to say I've been riding one for the past 2 years. My one's called an Ezee Liv. I've had a normal bike sitting at the back of my garage for over 10 years and probably ridden half a dozen times but with the electric bike I found I was using it every other day and actually enjoying every ride - meaning I get more exercise by using it (I peddle at the same time). I also found it safer because it can get across junctions very quickly and isn't so much of a hindrance to other vehicles (I tend to cruise along at approx 20mph peddling like blazes). I quite like unusual vehicles as well.
That's not to say it's been all roses - on longer rides there's always the danger of the battery running out and then you're stuck peddling a bicycle that's twice the weight of an ordinary bike. The battery also doesn't live forever, mine lasted 2 years and the replacement cost was quite frightening.
I'm currently riding my old bike everywhere and quite enjoying getting reacquainted but this is my electric bicycle: