Seriously though, I predict it like this: Del Piero to remain at Juventus for 2 more seasons, he will retire together with Nedved. Next in line captain Birindelli won't play much(if he's still playing anyway), so Buffon will become the club captain. He'll probably be that for around 4,5 +- years, before retiring or leaving. Chiellini will be the juve captain in 7 years..
Though who knows, this is crazy guessing as Chiellini might be sold within a year.. Buffon too, someone else stepping up as captain etc etc.