The seven books from J.K. Rowling about Harry Potter were a cultural event for over a decade. The lines at the book store soon transitioned to movie theaters as millions of readers flocked to see Harry Potter translated into real life. Nearly eight films and billions of dollars later we've run out of books to make movies on but that won't stop Warner Bros. from making more.
In a recent deal with J.K. Rowling, Warner Bros. will be making a new Harry Potter based film with assistance from the author. The film will be based on one of the supplemental books Rowling wrote called Fantastic Beasts and Where to Find Them which was also a textbook which appears in the Harry Potter world. No doubt that having Rowling attached to the picture gives this more legitimacy and the movie's story will have her pen behind it. The film won't have any connection to Harry Potter except existing in the same world and shared universe.
Warner Bros. is also planning other media versions of their new property including video games and other products. The deal also includes Rowling's adult novel The Casual Vacancy which is being made into a series by BBC but will be distributed by Warner Bros. probably for American consumption.
None of this should be a shock since Warner Bros. doesn't want to watch a billion dollar making franchise just disappear. I can't imagine they'll be wringing much more out of the Harry Potter universe, at least with Rowling, since not much was expanded upon after the seven books were written.