In the recent segment of DC All Access filmed after the Man Of Steel fan chat on Saturday, host Kevin Smith and director Zack Snyder dispelled the rumors that he actually started by having Harry Lennix read a passage from Frank Miller’s The Dark Knight Returns. At San Diego ComicCon Snyder clarified that he is not adapting The Dark Knight Returns.
In the segment, Kevin Smith says,
“Here’s what I think about adapting comic books to film. I don’t want to see this movie and I don’t think Zack’s trying to do Frank Miller’s The Dark Knight Returns. That will deserve its own movie, and god willing one day he’s going to do it. Somebody’s going to get there, and if anybody is going to get there it’s him.”
Snyder agreed saying:
“If you were going to do that, you would need a different Superman. We’re bringing Batman into the universe that now this Superman lives in.”
Here's the show (Their segment starts at about 2:11)