Thanks for the post. I'm very interested in hearing more real world experience with Dwolla, as there doesn't seem to be much out there. Presumably, the things it would be most useful for (larger transfers - where credit card fees are high, or p2p) are the most risky.
I will say, however, that the API is simple to use, and having a built in mechanism for charging a facilitator fee is great - but convincing my customers and merchants to use it will be difficult if fraud continues to be a sore spot.
http://www.shtylman.com/archives/319
This is not meant to be trolling; I genuinely want people to be aware of what they are getting into and understand the risks so they can avoid the problems I (and others) have already faced.