When I imagine the book being made into a movie I hear Enya soundtrack, maybe CaribbeanBlue and then maybe a score by Thomas Newman. I don't see this as a horror novel. There is magical realism and horror elements but it has a lot of heart. It's about a man fighting against his suicidal impulses and completely re imaging his life through art and creativity...with dire consequences, in Stephen King fashion. Wireman, while not infallible, is a kind of sage to Edgar, guiding him and supporting him in his new world. I heard Darabont was directing King's short story, The Monkey, but this has his name written all over it.
Last thoughts: King began to conquer new territory with his books The Green Mile, Bag of Bones, Lisey's Story, and Duma Key. What I mean is that he seriously tackled subjects like losing a spouse, child, or even mortality itself with more aplomb and contemplation. While he doesn't fundamentally change his style I think he shows growth and maturity in this new landscape. I've never seen this more evident than with his new story collection, Bazaar of Bad Dreams.