The current writer also penned the great (IMO) Aviator.
"GV: We're prepared to make it an R-rated movie. I don't intuitively see it as PG-13. The content and the graphic nature of the story itself is smarter than that. It's not for young kids. The utopian references and the way the characters and world are drawn in that delightfully inspired Jules Verne and Ayn Rand style places the film in a more elevated realm. It's the realm of a graphic novel. It has to have that edge. There's sort of that "Manchurian Candidate" psychological element in there as well."