I too am looking forward to the new book. I enjoyed the HP series, and so did my two boys as they grew up. It's funny to hear people disparage the writing ability of popular writers like Rowling, Meyers, and Brown, but I enjoy reading these "mediocre" authors (who write far better than I could ever hope to). Yet, I'm bored to sleep by many of the greats of literature.
By the way, I've heard speculation that Rowling's new book may be a mystery. Regardless, I plan on reading it.