Firstly, because in my years of teaching experience, nothing excited reluctant readers as much as Harry. Children who would ordinarily have baulked at reading read him. Then they went on to read other fantasy; Narnia, Diana Wynne Jones, Eva Ibbotson, Jenny Nimmo's Snow Spider trilogy, Susan Cooper's The Dark is Rising series and Philip Pullman.
Secondly, because Harry's success renewed interest in these writers, some of whom were out of print, and publishers invested more in promotion. Jones' Chestomanci series was reissued with new covers, and her out of print novels were re-issued. Philip Pullman's His Dark Materials trilogy is of course wonderful without the comparison to Harry, but I wonder whether it would have got the critical attention without the comparisons, despite Northern Lights being published before The Philospher's Stone.
And thirdly, because while some of the media attention geared towards Harry Potter has been about the media attention the books and films have been getting, I am grateful for the critical attention children's literature now gains. All the broadsheet papers now review children's literature and British university English departments frequently have undergraduate modules in children's literature, even those without an Education department; this I think is crucial as children's literature is being viewed from an aesthetic perspective rather than a utilitarian one; that is the pleasure of children's literature is being examined rather than its use in teaching reading.
So where now for Potter fans? In my opinion, the books' fans are better catered for than the films'; witness the dreadful film version of The Dark is Rising; the ongoing "development" of the Artemis Fowl film (rarely a good sign), and there seems to be no second Alex Ryder or His Dark Materials film. Of course, we have The Hobbit to look forward to.
There have been lists of books for fans to go to; this one from Time (scroll down to the end of the page) and from The Guardian. However these do focus on what is often more of the same, and I responded to this discussion on diversity in children's literature. So much European and North American fantasy is of course based upon Norse, Celtic, Greek or Roman myths alongside Judeo-Christian imagery of death and redemption. Two authors I've read recently who do not come from these traditions are Chitra Banerjee Divakaruni and Nnedi Okorafor. Both these authors are now based in the USA, but Divakaruni was born in India and Okorafor in Nigeria. Once again, the joy of Twitter! I encountered Divakaruni in an article on Indian Young Adult fiction tweeted by one of the Indian tweeters I follow (sadly the link is now broken), and Okorafor via the Books and Adventures blog.
Divakaruni is the author of the Brotherhood of the Conch trilogy (The Conch Bearer, The Mirror of Fire and Dreaming and Shadowland). I have read the first two, and have the final book on order. They are the story of Anand, a boy who encounters an elderly man in the streets of Kolkata in The Conch Bearer . The old man is a healer, on a mission with the magical conch; he is being followed by an evil magician intent on co-opting the power of the conch for his own ends, and Anand and a street sweeper called Nisa must help defend the conch. The journey from Kolkata to the Himalayas and the adventures the trio encounter are a fairly traditional quest story, but the Indian setting is beautifully evoked, and Anand in this novel has few powers of his own. However the Hindu aspect of the story makes it stand out; the Himalayas of course are the home of the gods, and a mongoose helps Anand and Nisha at one point of the book. A Hindu god is represented as a mongoose in art.
The second book is The Mirror of Fire and Dreaming, a far more interesting book in many ways. Nisa and Anand are now settled as apprentices with the Healers in their home in the Himalayas. Nisa is taking to her studies with enoyment and ease, but Anand is struggling to find his place. Then news of danger comes from Bengal, and Abhaydatta the healer travels there with an apprentice. However Anand has a vision telling him that something has gone terribly wrong, so he steals the conch and he and Nisa travel through a portal. They are separated on the way, and Anand loses the conch. He discovers a magic mirror, and stepping through it, he arrives at the court of a 16th century Moghul emperor. The period details of the Muslim court are beautifully evoked, especially the food- expect to feel hungry much of the time while reading this book!- and the time travel aspect of the book works really well. The separation of men and women in the Moghul court mean that the devices used so that Anand and Nisa can communicate must necessarily be magical, and I was reminded of Aladdin in the parts where Nisa and Anand meet in the gardens.