Let's suppose that the management has a short sight and is ungrateful enough to sack Monsieur Deschamps. Who are the coaches that may take charge of the team? Two possible coaches to me; Lippi and Prandelli. Lippi is way better than Capello, he is willing to coach the team and most importantly he isn't working now. Prandelli, as Lippi, is a Juventino and he proved that he is a classy coach.
Also I agree with the point Seven mentioned. Del Piero isn't just the team's captain, but he has a higher authority in the club which he's gained through the years he's spent in Turin. This means that it is very hard for Capello to sit on Juve's bench again.