In retrospect, I understand why Plan-B didn't keep the "documentary" theme of Brooks' book. Ego, pure and simple. Brad Pitt runs Plan-B. He likens himself the action-hero, hence the change from an after-the-fact documentary format to a "race to save the world" action-hero theme. He wants the be the central figure, rather than simply a narrator. One of the reasons I so enjoyed the book was because it tells the story from beginning to end, from the first days where people either didn't recognize what was happening or were part of the effort to cover it up, through the period where society collapses ("The Great Panic"), through the turning point, and finally to the post-war era, where society has been profoundly changed. Most every other zombie movie goes from normalcy to total apocalypse through a plot device: main character goes to sleep one night (or is put into a coma) and wakes up and finds the world in chaos. The zombies in the teaser seem more like the army ants in the fourth Indiana Jones move, with a hive mentality. Most disappointing.