The company I work for buys other companies all the time. Seriously, it's about 3 or 4 times a year. We get emails like that one when the rumor mill is turning, but not all of them come to fruition. It's just a way to cut down on the gossip, rumors and panic. Of course it never fully calms people down, but it does take some of the crazytown feel out of the atmosphere when all the employees are trying to figure out what's going on.
What I would be more interested in would be a period of complete radio silence between management and employees, as the SEC has some pretty rigid guidelines on what you are and aren't allowed to say during those critical final phases of a merger or acquisition. When these guys stop talking to the press and to their employees, we'll know some big announcement is on its way--- but even then we won't be able to predict the outcome.
I'd say it's still hinging on the two things it's always hinged on: the AA creditors' acceptance of the plan, and regulatory approval. Everything else is just for show.