Boldin has been asking for a trade since the 2007 season because he believes he should be paid like a No. 1 receiver. Boldin says that the Cardinals promised to rework his contract after the 2008 season, but it didn't happen and there were numerous rumors that he'd be traded.
The Cardinals had no real incentive to trade him if they didn't get the right offer, so he stayed a Cardinal and is now saying that he will not ask for a trade. However, despite his seemingly softening stance, he wants to be traded as much as before.
He probably realizes that whining and complaining, whether he's in the right or not, drives down his price for other teams who may perceive him as a problem-child.
He's in the final season of his contract, so the Cardinals would be wise to move him and get something for him before he hits free agency, but they will still not give him away. They will most likely ask for no less than a second round pick from the Dolphins, or anyone else for that matter, and will not trade him just for the sake of getting something for him.
They would instead keep him and get the production out of him for another year rather than giving him away to the first team to offer a third round pick, reportedly what the Dolphins are dangling.
The move would certainly make sense for the Dolphins who, with a No. 1 receiver, would have everything their offense needs. They would have a young and promising quarterback in Chad Henne, two very good running backs in Ronnie Brown and Ricky Williams, a very good offensive line, and the No. 1 receiver they so desperately need in Boldin.