I guess the Jays are willing to trade Rios, if the rumours of him going to the Giants for either Cain or Lincecum are true. The Jays want Cain straight up, but the Giants would prefer to give up Lincecum, and the Jays will only do that if SF takes on Glaus and his contract, too.
I'd say the Jays should just throw their hat into the Santana sweepstakes if they're going to trade Rios, who's better than any OF the Yankees or Boston would give up, but there's no way they could re-sign him.