I won't ask you to look to 2 seasons ago. I will simply say just look at the last season. He played less than half of the season due to injury (which wasn't his fault, all players were injured last season) and still managed to excel (in comparision to the rest of the players) and come on top with 11 goals.
He might not be 25 anymore, but thats just normal. In my book, if Del Piero is physically fit he is the best bet we have at any game to win. He is a player that is astonishingly skilled, mind blowing vision, magical free kicks and a great finisher too. He might not have the speed he used to have (although he was never a fast player), but he's compensating that with immense amount of experience.
Its funny that every beginning of a season all you naggers will come out asking for del piero to retire or leave and when the shit hit the fan you come back on your knees waiting for him to pull his miracle, which he ends up pulling one game after the other.
Just be grateful that Del Piero is still part of this team, because rest assured the day he retires Juventus as a team would have lost ALOT of its fear factor.