I just saw on french TV an interview with Zidane about his incident. He appologizes for the act because it sent out a bad image and thinks of all the kids that have seen it, but he isn't ashamed for it, and said that it wasn't "blowing a fuse" but a reaction to an unsupportable insult, which he didn't repeat, but which did involve his mother and his sister in an untolerable way. He said that Materazzi said it once, and he asked him not to say that. Materazzi said it again, and he walked away. And then Materazzi shouted it again at him, and he told himself, ok, that's enough now... and he hit him. When asked if he'd do it again, he said that he could not say no, because not reacting would amount to accepting the insult, which he won't. But he regretted that it happened, and accepted also that he was punished for it - only, he found it unfair that the reaction was punished and not the provocation. In his view, violent words can be worse than physical violence, although both are bad things.
To the referee, he asked whether the referee really thought that during a world cup final, at 10 minutes before the end of his career, he'd do something like that if not seriously provoked, and whether it is not rather the provocation rather than the reaction that ought to be sanctioned.
He said that,yes, sometimes he's violent when provoked, and that's his dark side, but he's an honest man who will always try to be honest and defend his honor. If that implies punishment and other loss, then so be it. A bit fatalistic, he added: if this is how things are meant to be, then I accept that and I assume responsability for it. This is the way I am.