Actually they are obligated to use it as leverage in negotiations, if negotiations fail, then they can "brief" the court as part of the authorized discovery process..i.e. Quinn on Project West.
The whole idea of settlement is too keep the skeletons buried. Disgorgement will be very public and will get messy as per the DOJ on Insider Trading prosecutions. I am sure the DOJ is alrezady working on indicting these hedgies, they have to be or they would be in violation of the public trust and in an election year they have way too much heat on them as it is. No, they will be going after the Big Fish, so they can show the OWS and Tea Party people that the Obummer Admin is prosecuting more IT cases than the previous admin.
It is all about numbers, not people when they play the game. Fast and Furious is a high-level authorized action, to counter Wall Street will need to suffer.