Sure, I agree with the thoughts on the secularization thesis and the rationality of magic. I even concede that Harry Potter might be good in large part because they are so secular, and that all the action in the stories comes from the characters themselves, not some outside influence like God or the devil, and I especially appreciate his head nod to Phillip Pullman's His Dark Materials trilogy. But Harry Potter is anything but modern.
The ethical dilemmas that the characters face throughout the books seem particularly cut and dried. The ethical issues that Mika is speaking of, I believe, are not so much ethical issues but more questions about where loyalties lie, and attempting to reconcile perceived loyalties with actions. For instance, ever since year one Harry and the gang have suspected Snape as being a "bad guy," but Dumbledore's assurances of his allegiance to the "good guys" has caused tension. There isn't tension in trying to choose the right action, there is tension in reconciling Snape's actions to the trust that a respected figure has for him.
Furthermore, the moral quality of a character is distinguished specificity by the magic he uses. Dark Magic is shunned even when the spell itself is not inherently bad. For instance, The Unbreakable Vow is a Dark Magic spell that Mrs. Weasley almost had a heart attack over when Fred and George tried it, but how easy would it make things to use Unbreakable Vows to enforce contractual agreements? The ethical status of certain types of magical actions is already presupposed to be good or evil, inherently, without even a question as to the consequences. It is decidedly deontological, and totally indisputable.
While I'm on the topic, it might be beneficial to point out that all the Hogwarts kids do celebrate Christmas (although there is no mention of Easter). This doesn't necessarily denote religious tendencies (I celebrate Christmas and am decidedly non-religious), but does seem to indicate some religion involved. Perhaps Rowling has left this ambiguous in order to remain as secular as possible?
When it comes down to it, Star Wars is much more philosophically inspiring than Harry Potter. The newest Star Wars film raised a variety of ethical questions, whereas Harry Potter is simply good, fun reading.