I think Dirk needs to leave Dallas. His time there is up and he needs a change of scenery after failing in the first round soooo many times. He is a superstar, offensively, yet, he is not going to win a title in Dallas unless they bring in a first optioned superstar or a first tier captain with leadership skills and and overall "team" mentality.
I think Dirk has proven that he can't achieve this, Cuban has put so many different weapons around him and he still comes up short...
However, you put him in Miami with Wade, instantly the Heat move up to number 2 maybe even number 1 in the East. Wade has proven he can win a championship (yes he did have Shaq too) but he has that killer instinct that Dirk lacks to be the teams number one guy. Dirk and Wade in Miami surrounded by Haslem, a young Beasly, youngs like Wright and Chamlers, get a legit vet point and a defensive minded center, that team wins the championship hands down.