Apparently anyone selling any type of virtual currency on ebay or craiglist is now a money transmitter, and as such a MSB, and as such now in violation of FinCEN interpretation if they haven't registered as an MSB.
There has to be some lawyer out there who is interested in Bitcoins and who can offer their interpretation on this matter.
Yes, me. I wrote up a quick take for the Bitcoin Foundation here:
https://bitcoinfoundation.org/blog/?p=152