Personally, I am backing Vanessa. I don't see the big deal really. She took a private picture of herself, for her boyfriend, and it leaked. Thing do have a way of leaking, so you can't really say she did on purpose, as you have no proof she did so whatsoever. This, to me, shows that she is a real person, and that finally her "innocent girl" reputation floating around her constantly has been diminished. This is good to me, and like others have said, it is natural that everyone has a body underneath clothes. If someone more like Britney (I am just using her as an example) was to have this happen to her, people wouldn't react like they did to Vanessa. And for the record, Disney are keeping her, thankfully.
As for those, who are saying things about HSM/HSM2, that it is stupid, you would never watch it, you really have to realise that it is just a bit of feel-good fun, and everyone needs that in their lives at some point. It was initially made for kids, but it blew up so big, because adults also did like it.
Vanessa has issued an apology, end of.