He is one of the reasons I liked season 5 so much, the actor and the character are perfection. He is in the pit, I think he's going to stay there .It would be interesting to bring him back, but I think it would be counter-productive.
I haven't watched season 8, but last I checked, he's not dead? He's in the cage with Adam and Micheal? Sam stopped hallucinating him, but he's not dead.