This release has been released:
A couple of interesting points about all of this. Avery was in Dallas for about six hours on Monday. He had a physical with a doctor so that the Stars can make sure he is completely healthy. That's important in case he gets hurt in the minors. It's also important for sending him through waivers (for reasons of the CBA and insurance).
In talking to people here, it appears Avery had no interaction with anybody on the Stars in his time in Dallas, only with the doctors. He also supposedly is already on the practice ice in Hartford this morning, and the New York media is already there, and the Rangers PR people. So read into that what you like, but it sure looks like the Rangers are angling to make him a Ranger once again