I said a similar thing in a mailbag recently.
There is a difference between Wade Redden and Brian Campbell. Campbell can play over 22 minutes a night and run your powerplay, while Redden is a third pair defenseman who spent a year in Hartford because of his salary. Redden may have been a good influence on young players in Hartford, but he still won't bring any sort of value to his contract in the NHL. The Blackhawks were lucky that the GM who signed Campbell to his contract is now somewhere else and was in need of adding salary.