Twilight isn't ruining the occult world. Don't get me wrong, I'm against Twilight and all it's subtle misleading, but I wouldn't give it that much credit. At the most, it's lowering the standards of literature and proving that pubescent girls will eat up anything with similar characteristics.
It may ruin the dark and mysterious image of traditional vampires. I recall a friend telling me they went to some sort of Dracula stage production and she heard a girl say, "It's just hard to get used to seeing vampires as bad."
I don't see anything directly occult related because I myself wouldn't consider vampires or werewolves as occult.