It would be amazing if they did though! I'm surprised to hear they've passed on it. It would really advertise, I think. It might really get in the way of guests though. That's the only problem I see.
Since most of the book takes place at night after the public is ushered out, I think it would have minimal impact. I'd definitely go see it and buy the DVD.
I thought I heard him on Lou Mongello's podcast about a year ago. Supposedly, they had looked at it with some interest, but not enough to go all out and do a film. At least not right now.
Perhaps someday, in some form, it might happen, but it would present a whole bunch of problems like how much realism to add and how many of the backstage secrets should or would be allowed to be used.
Even though it wouldn't interfere much with guests, it would definitely disturb the amazing things that go on in the park after guests leave by the unseen Cast Members that keep it pristine.
Oh, we're not sure if it's going to be a movie or not. The thread is only about asking if anyone knew about Disney making it, so unfortunately right now they aren't making one as awesome as the movie would be.