The Brian Shaw and Dominique Wilkins situations were different than Childress, as one was basically holding out and the other was aging and didnt want to go through a rebuilding process with the celtics (and he did go back to Europe later).
And Childress is signed for another 2 years (with opt out options for him), so I don't know if he gives that up. He turned down 33 million for 5 years with the Hawks because he got 20 million tax free for 3 years, so when you add in taxes and etc, you are talking about him making almost twice the MLE.
And Waltzero, as a restricted free agent, the hawks only have to extend a qualifying offer to keep his rights. I think the becomes a UFA next year, though.