Am I the only one among friends and colleagues who is not re-reading, re-watching, re-living - and mourning the wonderful years that are over now? I don't want to sound like a snob but I honestly don't understand what it is all about. Come on, folks, the stories are not over after a movie opening! They will be there forever, or at least as long as there are readers who are interested enough, and that's something nobody can predict.
I cannot imagine similar laments when The Last Battle was published. It was just the beginning of a new story. And as promised, new stories came and will always be coming, and some of the old ones will stay and some will perish and some will be rediscovered. For some readers, Harry Potter will always have been around, just as for me Alice in Wonderland has always been around. But I don't mourn that Carroll is dead and will not write more Alice. Other people have done this after his death, both More Alice, and Automated Alice and Digital Alice, you name it. There will be more Tim Burtons to make new movies.
And Harry Potter will be forgotten or remembered, and there will be new generations of readers who have never read Harry Potter, and there will be people who have lived and died without having read or watched Harry Potter, and there will be people who start reading Harry Potter and don't know now it ends, and there will be people paying fancy prices for first editions (I have some), and there will be readers saying that Tolkien and C S Lewis pinched all their ideas from Harry Potter, and there will be critics putting Harry Potter in footnotes as a minor text from the turn of the century, only of interest as a context for Skellig.
Mind, I have written extensively on Harry Potter, and I re-read the first six volumes when the final one was about to be released, but only because I had an essay to revise urgently, taking the last novel into consideration. I think I have seen the first three movies - they are all mixed up in my memory. I have taught a whole course on Harry Potter several times, and I always re-read books that I teach. I may re-read them all again at some point, and I may even watch the new movie when it's available on DVD.