So it sounds like Cardinal Ratzinger was not 'denouncing' Harry Potter, he simply made a statement in response to a question about an article in which some woman was railing about the books that we need to be careful about what we read. What enters our minds, can influence us, if we are able to be influenced. Sounds like good advice, but I and my kids have all ready Harry Potter. We have discussed them, and our Faith has not been shaken by them.
I don't think that Pope Benedict spares one thought for Harry Potter, and the idea that he has come out full force and denounced the books is preposterous!