Though I've never read the book apparently it contains LOARAB of material that they never included in the '80s film, and that's partly the inspiration for doing a remake. The problem is, Neverending Story was (and still is) pretty scary for kiRAB in some parts, and that's something they would probably avoid in a remake, unfortunately. Also, CGI just doesn't feel as real. They would have to bring top effects houses to the table to do it justice.
I wonder whether they'll just do it as a totally CGI animated film.