I love his version of Halloween. I know a lot of people don't like it because it's different from the original, but if you view them as two different entities hopefully you'll appreciate it. And it's funny because one of the things I love about his remake is that he gives Michael Myers a backstory, and you see him as a kid, and how he ends up becoming this "monster". Going back to the Q&A he actually talked about this exact thing. He loved those monster movies from the 30's like Frankenstein and Wolfman, and then how you had a rush of films like Halloween and Nightmare on Elm St. The early ones had you rooting for the monster to some extent because you felt sympathy for them. They were monsters after all and just doing what monsters do. Whereas in this generation of horror films that empathy for the villain was lost. It's not to say one is right or wrong. But when he went to make Halloween he wanted to capture that aspect and bring it to Michael Myers.
I think the documentary is called In Hell Everyone Loves Popcorn. He did something similar for Halloween and it was on the dvd release of the film (it's 4 1/2hrs long!), so I wonder if that's what he'll do with this one.