As it stands now he is set to gain everything from this attack. You have to remember that before this attack he was under serious pressure from all sides. He is under investigation for massive corruption and has sex scandals hanging over him. By getting attacked like this, sympathy will stream in I bet, and for a time at least focus will be on "poor old Berlosconi" and not his corruption and sex scandals.
As I said, I would not put it past him one bit that this was staged. I even believe the rally he was at was a freaking anti-Berlosconi rally, so why the hell was he there?