Check out this article that interviews Daniel Handler, author of the Lemony Snicket books
http://www.comingsoon.net/news/topnews.php?id=6466
Here's a quote I liked from the interview:
"Carrey, in particular, has been fascinating to watch, he says. "He's either naturally a snide villain, or he's been in character the entire time," he says. "He really scared me."