From what I understand its only uncontracted players than can be grabbed - sort of like GC having the first 16 picks in the pre season draft?
Even then, I'd think that the likes of Riewoldt would ask to be traded (out of loyalty to the Saints) so he'd likely earn the Saints a high draft pick.
So I wouldn't think we'd see much more than what we do in a normal PSD with perhaps a couple more quality players sliding through.