I don't think Sharpie should be swayed by pleading from Deans or O'Neill. If he feels like it's time to hang 'em up then he should just do it. He's been treated pretty shabbily at times in the last couple of years and would be well within his rights to tell the ARU to piss off. He said in an article in the West a couple of months ago that he'd had to apologise to his boys for prolonging his career that little bit further. Family could decide this for him.
He may, however, feel that he owes his team to stick around so they aren't without a senior player as captain. I'll say this for the big fella, he steps up a level as a player when he's leading them. I used think he was lazy and overrated before he came across to the Force, but the captaincy transformed his game. He seems to relish the additional responsibility.