The "spin" and insta-polls will always make it appear that the leading candidate "won" because there's no immediate evidence that the opponent turned it around. Most of the US media reported that Bush "won" the first debate over Kerry for a day or two. Moreover, given the late date, and the small number of voters whose opinions matter (Bayrouistes wavering between Royal and a blank vote; LePenistes wavering between Sarkozy and abstention; left-leaning voters especially older men wavering over whether to vote for Royal), we won't really know if this had any real impact until Sunday night.
That said, she was much, much, much better than she's been the entire campaign. She was sharp on most of the facts -- whatever you want to say about "electricity" vs "energy" she won the point, because Sarkozy conceded he didn't know the dossier -- and most of all, on the offensive throughout. She never let his attacks, now matter how snide, go unanswered, and when he was most snide ("Hollande ... ca ne vous concerne pas?" ..."je ne vous parle pas dans cette facon ...") she was the sharpest: "Vous pouvez debattre Francois Hollande quand vous le souhaiterez," ...." Moi, je ne mens pas.")
The "summum de l'immoralite politique" was clearly a set-piece and she used it at just the right time, though I think she kept at it for too long. She made her point clearly and sharply and should have let him stew in it by asking him to respond, rather than letting him escape with his pre-planned "il faut du calme ..."
Sarkozy's tic to turning to LA Chabot as if appealing for his mother to break up the fight came across as pathetic, and while I think Lupin is wrong on most of his points, the "broom up her ass" has been a problem for her throughout the campaign. She was much less stiff, much more animated and loose last night, than any other time I've seen her, especailly last Saturday.
What gives me some hope is that from anecdotal evidence (mostly reading and hearding), the hesitation of a lot of center- and left-leaning voters, esp older voters, had to do with perceptions that she lacked toughness and personality. I think she showed without a doubt last night that she can be tough, and she showed real passion (though it did appear pre-programmed that it rushed out all a once, then went away by the end. (She seemed exhausted by the end.)
Obviously she did not succeed in making Sarkozy blow a gasket but we knew he wouldn't, not last night. But just as he's had years to build up support on his right that he won't lose, he's also had years to terrify the center and left, and that won't go away from two hours of staying calm.
What might change is that some of those hesitating to vote for Royal might have seen enough to close the deal. It certainly gave enough inspiration to Bayrou, who had nothing more to gain, to come out against Sarkozy this AM.
She's got a terrific attack on Sarkozy's program in her "Lettre aux francais" published in at least one of today's dailies, and without a doubt, she's had a much, much better entre-deux-tours than anyone had expected (especially after her dismal speech the night of the first round).
I think there's some chance that among late-deciding voters, she's at least created a perception of a meaningful vote, and although I'm as skeptical as I've been for 2 years of her chances to defeat Sarko, I'm as impressed with her this morning as I've ever been.