I consider the appropriate role of magic in kid lit to be the same as the appropriate role of magic in reality—though it will look different. This is, after all, an extraordinarily magical place. Sunlight makes trees out of thin air (literally), tadpoles turn into frogs, human love turns into children, and you can trick the air into lifting an enormous steel bus full of people up to thirty thousand feet if you know how to curve a wing and harness explosions. And it’s not all cheerful, happy, kittens-in-baskets magic either.
What happens if one of our wizards splits an atom? I think magic in children’s books is at its best when it wakes kids up to the mind-blowing magic all around us—when it overcomes the numbness of modernity and makes them watch an ant war on the sidewalk with all the wonder it deserves. Ironically, Christians, who profess outright to believe in magic (what else is water into wine, resurrection from the dead, calming storms, etc?) are the most upset when you put it into a book, while authors like Pullman (a materialistic atheist who believes reality to be all mechanism as far as I can tell) works with it comfortably and well. It really should be the other way around.
--ND Wilson in an online interview that i'm too lazy to link to at this moment (by the way, let this serve as a not-so-subtle reminder to the future Dr. Addcox to bring me book back to me)