I feel no impulse to defend Harry Potter on the grounds that the books follow this sort of higher fantasy tradition -- frankly, there isn't much in the Potter books that strikes me as numinous. There's nothing there to fill one with the sort of awe you feel in a great cathedral, or when reading of Arwen's death, away from all family and kin, without another soul beside her, Aragorn and immortality both gone. But this seems utterly irrelevant to me. For some reason, Byatt (who ought to know better) completely ignores the "non-numinous tradition" (for lack of a better word) of magic books.
From Alice In Wonderland to James Thurber's delightful fairy tales The Wonderful O and The 13 Clocks, to The Phantom Tollbooth, there is a heady and wonderful ancestry of magical books that Harry Potter fits as easily as a missing puzzle piece.
At the moment, I'm looking at the sense in which wordplay (which is a rather rarified pleasure, or at least not a sensory one) is still part of ordinary life.
(The essay is from 2003--no spoilers for anything current.)
Link from cija in this thread.