Here's my idea for the new trailer:
It starts out very somber and dark like the first trailer, all narrated by Roschach's opening narration. Until eventually, we cut to the arial shot of the button, as we get a look at 1985 New York, and the Music changes to Stop hey whats that sound by Buffalo Springfield, and from there it begins to lay out the beginning of the book. We see the Dan-Rorschach scene, and for a short while, their dialogue narrates images of modern superheroes, maybe even a few Vietnam shots. The music stops, and maybe stwitches to something bigger like maybe E.S. Posthumous's Tikal, get a few scenes/images introducing us to the danger of the whole concept, maybe a bit with Dr. Manhattan, and then they show us the characters going back into action, and then we get something like a fast-paced version of the trailer, with more tense action bits.