This is what the Pope has to say about Harry Potter on his very own blog, Musum Pontificalis
My judgment on the matter is quite astute. If you doubt it, just consider that you most likely don’t let your children watch everything that is on TV or buy them nudie magazines. The Harry Potter series is about witchcraft, and the moral dimension contained within it is defined by witchcraft. It would be imprudent to assume that all children will not be influenced by it. In conclusion, just have some discretion on what you allow to influence your kids and then get on with it.
“Come on, people; get a life.”