So, I imagine there is a small army of Mavs fans who are either despondent, or have bypassed the first several stages of grief and gone straight to "lynch Mark Cuban" anger. To you I offer these words of comfort and coersion.
The biggest point of furor will probably be that Dallas let Tyson Chandler leave to play for the New York Knicks. Does what's happened today make that a bad move? I don't think so. The move was made so that Dallas could have a seat at the table with a superstar, the kind of player who would make Dallas a championship contender now and for the era post-Dirk. Chandler was not that player, love him as we all do, and Deron Williams will not be the last superstar that Mark Cuban will get a chance to bring to Texas.
We had a 50/50 shot. That's about as good as you can ask for. For all the whining that may take place over how Dallas has never wooed a "big name" free agent...they were also never, ever this close.
Now, yes, there is a vacancy in the "super-sidekick" role next to Dirk. But there are others who can audition for that role. Steve Nash, for one. Don't forget that the Nets have effectively taken themselves out of the running for Dwight Howard. Chris Paul is also still scheduled to be a free agent in a year's time.
Letting Tyson Chandler walk was the right move then. It's still the right move. Dallas will survive this.