According to director Albert Hughes (The Book of Eli), Warner Brothers wants a movie that is at least PG-13, and the project will continue its development this year, with the script possibly ready in September.

"There's something about cinema — old cinema", the director says,"where I get excited about some subversive things you can do with being held down by something like that or being censored. That I kinda found to be a challenge, how can I make this feel like a rated-R movie. I look towards what [director Christopher] Nolan did with Batman. Tonally, those don't feel like PG-13 movies."

Hughes said that the trick to achieve this effect was to simplify everything for the audience, bearing in mind that certain elements of this manga are too complicated to translate them into film.

As for the possible cast, Hughes said it was too early to give names but he's looking for a young and talented unknown actor, as well as a Gary Oldman or Morgan Freeman type of actor.

(Source: ANN, Film School Rejects)

It seems that they want to take this movie seriously, but at the same time it looks like it won't be very faithful to the manga because we know what happens when directors and producers speak of "content too complicated for the audience"
O_O