My sources: watching the match on TF1 myself, so saw Villeneuve's horror show. (One of the questions was: This is the first worldwide sporting event of your presidential mandate. Do you wish to send out a worldwide message?) I didn't immediately realize they weren't cutting to Sarko during the match, it came to me later.

The special preparation has been commented on here and there. See the first commentary in L'Equipe by Laurent Bénézech, former international, and this  article from Le Monde.

The video of Sarko's dressing-down was on Michel Denisot's show last night on Canal +. I only saw the end of the sequence. Present on the set was Sylvain Marconnet, absent from the French team because of injury. His reaction was to say that, in the state of dismay the players were in, the president's words would surely go straight to his team-mates' hearts. Said with a tight little smile.