I'm amazed there are people doubting that this could happen
A new GM would have no ties to Marshall or Dansby or anybody else for that matter. He would come in, take a dispassionate look at the roster, and hopefully make some big decisions. If he decides that he can get a better player for the same money or the same player for less money or two starters for the same money then a good GM is absolutely going to do that - it's his job. Of course, in the first instance the new GM would be seeing if he can get a draft pick in return but if the other 31 GMs also think they can do better then there won't be much interest. Look around the league. This year you saw Pro Bowlers being cut because teams can get better value for money elsewhere and because there is no cap hit.
What's more, the 2012 offseason is going to have a much bigger free agency pool because of the new CBA. There are going to be a lot of good players on the market with just 4-5 years experience (they can't all be franchised) and everybody knows it. For once Free Agency is actually going to be a big deal and the new GM is going to want to be a big player there and he's going to want to have the cap room to make a splash.