These days att is getting a little stingier with releasing you from a contract, but if you chat with the right persons and have the right reasons to get out of an eta, it might work.
Just dont waste your time on the att wireless forum asking this question. tht place is full of snarks that will try and "tell" you what do to when its your phone, your services, etc... their response will be "read your contract"... yada yada... they need to get rid of the goon-mods over there and turn that ghosttown around