Downs, Gregg and Olivo all turned down arbitration with Jays; so, in addition to pick from John Buck leaving the Jays would get 4 round 1A picks in next June's draft if all of Downs, Gregg and Olivo leave.
Jason Frasor will be back next year because his status as a Type A free agent made it difficult for him to get offers from other teams. If he had been a Type B he likely would have turned down arbitration because then the team he signed with wouldn't have to give up a compensating draft pick for taking him from Jays.
Downs leaving will also bring them something like a second round pick from the team that signs him.
http://www.tsn.ca/mlb/story/?id=343612