So, in a number of circuits, the AUSAs are agreeing to appellate dismissals or motions to remand. That's happening now.
In the Sixth Circuit:
The gov filed a letter in U.S. v. McCray, No. 11-3249 (6th Cir. July 20, 2011), saying:
"In its brief, the United States argued that the district court had not erred. Upon further consideration of the proper interpretation of the Fair Sentencing Act, however, the United States is now of the view that the Act’s revised penalties apply to any defendant sentenced on or after the enactment date, August 3, 2010—including McCray."
Gov acknowledges Carradine, but says it is distinguishable.
In the Seventh Circuit (where they face the adverse Fisher decision), there's a tiny rumor that the gov may seek review en banc on the issue (the rumor is based on a filing in another case) or seek S Ct review.
Nothing really definite on 2255s. Not yet....