If the Bayern München FO allows a Müller transfer they're facing a fan riot and the next annual general meeting will be a living nightmare.
Such a deal would cause disturbances within the club for the foreseeable future and that's not what you want when your team is eying the Champions League final in Berlin 2015.
So I know you guys don't wanna here this, but now way this is going to happen. Anyway, I think Müller is using the opportunity of LvG's offer and his unparalleled popularity among the fans to push his agenda. With Robert Lewandowski coming from BVB and Mario Götze being expected to raise his game he's facing unseen competition. Meanwhile Müller absolutelyhates being benched for the important games which is why we're seeing this opportunistic behavior, he's probably eying certain guarantees about his role in the squad or simply a payraise to make a place on the bench easier to bear.
I don't know what it is yet, but he's not seriously interested in leaving unless he's told to go which will not happen because of the above mentioned reasons.