I watched Montebourg and Hamon on TV tonight at Montebourg's Fête de la Rose. Both seemed slightly inebriated and full of swagger. They're not trying to conceal the fact that they've thrown a dagger directly at the president. And Valls' office says that they've crossed "une ligne jaune." So, de deux choses l'une: tomorrow they will be fired, and the government will be plunged into a deep crisis, or they will be let off with a reprimand, and Hollande will lose whatever semblance of authority he has left. Either way, Hollande loses, and Montebourg probably steps out ahead of Valls in the polls as the most likely to succeed.
What happens between now and the next election is anybody's guess. A full-blown fronde in the Socialist ranks could make it difficult for Hollande to enact the revised Responsibility Pact or do much of anything else. A modus vivendi between the frondeurs and the Hollande-Valls axis is difficult to envision. If Montebourg goes, who will replace him? Moscovici could be recalled from disgrace; Sapin or Rebsamen could be tapped (both have been mentioned for the job in the past); or Hollande might strike a bargain with Aubry, who may retain enough credibility with the party's left wing to calm things down. But at the moment things are looking quite bleak for Hollande.