If there's anyone in the Washington DC area wanting an electric bike for a long-distance commute of 10+ miles, this is what you're looking for: http://washingtondc.craigslist.org/mld/bik/3218415010.html
I posted my opinion on ebikes in general at http://www.mrmoneymustache.com/forum/ask-a-mustachian/electric-bike/msg7672/#msg7672
, and my advice on whether this is for you still applies. As an update, I've been doing the same 16-mile commute on a cyclocross bike and it does take me longer in both directions than the electric did, about 90 minutes downhill and ~100 minutes uphill.
It's less than a year old and I'm selling it for about $250 less than the build cost (my $1100 quoted build cost was before I did the wheel and derailleur upgrade). Even though I'm trying to trade it in for a loss on paper, the payoff of killing my car addiction far outweighs it; it was essential to help me transition to all the time, all weather bike transportation. I've switched to a conventional bike and don't need this anymore.