My 2 cents: I personally have no opinion in the Harry Potter/Pokemon/Witchcraft/Eastern Mysticism debate, though I do tend to lean on the freedom-of-read side. I feel that just openly accepting these things could lead to some confusion when other more serious topics are brought into question, but "protective" parents shouldn't make an assumption about a series without looking into it. Also, to say that Harry Potter or Percy Jackson are witchcraft, you can step just a tiny bit farther and rule out Star Wars, The Wizard of Oz, Mary Poppins, and even most fairy Tales. I myself don't really read juvenile/YA fantasy any more, so this debate doesn't concern me directly.
Thanks for your time, Beckendorf