The novel was originally written for the small screen. Neil Gaiman actually wrote the novelized version of the BBC miniseries while he was on the set of that production. Apparently, the project has recently come out of "development Hell".
Slade will be using the original script from 2000. Neil is currently in the process of polishing it up a bit. Gaiman stated, "When it comes to movies, the dead certainties never happen and the things you think are dead come back to life. I have no predictions and absolutely no theories. I watch everything that goes on in Hollywood with amusement and occasional trepidation...but mostly amusement."