Wired's Danger Room blog has a post announcing that the DoD is allowing USB thumb drives, effectively ending the DoD-wide ban. Ostensibly, the ban has been lifted in certain circumstances, and will not be for everyone. Also, it is not supposed to be easy to get a drive. As an auditor, though, I've been to installations where USB drives were in rampant use.
None of the ACAs that our company does work for has sent out any kind of "official" notification. It will be interesting to see what actually comes out, and when.