Well, I just got my copy from Twin Palms publisher today and I must say I'm pleasantly surprised.
The final edit of the 30h of original footage managed to find an emotional continuity, with sights and sounds, but there is no story per se. It's a mixture of photography and music, but it's not necessarily cinema as we're used to.
The hour and a half follow the behaviour of various characters from Eggleston's circle. It's a sort of performance, if you will. Everyone performs before the camera. In contrast to photography that tries to be inconspicuous, and capture an authentic moment, video is utterly conspicuous, and captures something authentic, but much more crafted.
The book serves double usage as DVD case, so it's hard to say whether it's a book + dvd or if it's a DVD with an excessively developed case... It contains a short word by Gus Van Sant, and a collection of screen captures, worth checking.
As the editor mentions, in the extras, if you pick almost any single frame of the movie, you end up with a composition worth checking.
It surely avoided the danger of being a laborious and aimless movie. It's more like an essay in pictures. And the fascination with faces reminds me a lot of Chris Marker's Staring Back exhibition/book (available at MIT press).
All in all, something interesting.