Berlusconi, according to the usual unnamed sources, wants Fini to be punished, even to the point of requiring him to step down as President of the Chamber of Deputies.

I think this is unlikely. As far as I can see, no President of the Chamber of Deputies has ever resigned, unless to take up another, better post. Three Presidents of the Senate have resigned (Merzagora, Paratore and De Nicola), but Paratore and De Nicola both resigned in protest; only Merzagora’s resignation is surrounded by question-marks (I’m following Wikipedia here).

Nor is there any provision in the Chamber’s rules of procedure to vote no-confidence in the President of the Chamber.

Neither side wins from a protracted fight. I’m betting this blows over.