That brings up an interesting idea.  If the bitcoin volume is really as significant a percentage of Dwolla's revenue as some suggest, why couldn't a bitcoin business buy Dwolla?  If bitcoins are a large part of their revenue, it could be a profitable investment even with a significant loan.

A USD exchange needs something like Dwolla's existing infrastructure to take in cash efficiently for the mass market, and they probably make a larger profit per dollar moved than Dwolla does.