I had to do a forced gamertag change last night (1/25/2013), but after I change it and start downloading the new profile, it stops the download about 1/10 of the way in and says, "Profiles can't be downloaded right now. Please try again later. Error Code: 80151006"
I know that code means my Microsoft account isn't associated with a XBox Live account or whatever, but if it would let me download the new profile, then it could be associated.
I should mention I talked to a customer support agent last night around 11pm EST who said it's an emerging problem and basically I'd have to wait for it to be fixed.