The Big Dummy is Surly's recently introduced long tail bicycle. What differentiates the Big Dummy from other long tails is that it's designed for use with Xtracycle's modular components for the Free Radical system.
WCCO in Minneapolis featured the Surly Big Dummy in a recent newscast. You can watch the archived video here. According to the story, Surly sold 90 Big Dummies in about 4 hours the first day it became available. It was already backordered the first week the Big Dummy was available from Surly.
The Surly Big Dummies shown in the video are equipped with Clever Cycle's Stokemonkey, but the news people don't mention the electric assist.
More: Visit Surly Blog. Read discussion about the Stokemonkey (which Clever Cycles currently does not ship). To buy a Big Dummy, visit the Surly Dealer page. Surly is a brand of the big bike distributor QBP, so any bike shop should be able to order the Big Dummy for you. The Big Dummy is only available as a frameset, so you need to use a bike shop that will help you put the bike together and/or you really need to know what you're doing.
If I had a hat on, I'd tip it to Sveden of Minneapolis. See his Minneapolis / St Paul bike race calendar.