Apparently the old "Harry Potter encourages interest in the occult" stuff is surfacing again in the wake of the new HP4 movie. It's funny how people confuse the use of a genre (magical world) with moral endorsement. I wonder if those people have the same worries about magic in Narnia (or indeed in Lord of the Rings) where the good guys have quite a lot of magical power.
Another point my wife made was that in HP, magic wasn't a moral choice - you either are or aren't magical. The moral issue is then how you use the power you have - just like it is in the real muggle world we live in.