The guys you've listed that should retire could still beat about half the guys in the divisions they are in respectively. So it kind of depends on what level opponent they are fighting. I agree if you mean fighting for top status, but B-Hop, Tito, and Morales just came of decent performances against champions, they could still fight on and I wouldn't question them for a little while. Holyfield is a shell of his former self and needs to call it a day. Unfortunately I think he probably will continue on....Toney is pretty much done I just cant see him getting in proper shape anymore. Castillejo was in a good competitive fight but really took a big shot, he definately needs a long time off after that and at his age a layoff means it's probably over.