Zack Snyder Interested In The Dark Knight Returns Movie?

At the Watchmen panel, Zack Snyder expressed his love for Frank Miller's The Dark Knight Returns, in response to a question about the more mature direction of comic book adaptations.

"There are a lot of other graphic novels out there, but I would love to see Frank Miller's Dark Knight made into a movie, but that's just me."

Later at the Entertainment Weekly Visionaries panel, Frank Miller told Snyder "You can do it anytime you want to Zack". To which Snyder said he was making a note of Miller's response. Now I know this is very speculative, but even Batman producer Michael Uslan has already expressed interest in a possible adaptation.

Miller's four-issue comic book miniseries, Batman: The Dark Knight Returns, was first published in 1986. It has since become one of the most popular graphic novel/trade paperbacks of all time. It reintroduced Batman to the general public as the psychologically dark character of his original 1930s conception, and helped to usher in an era of "grim and gritty" superheroes from the mid-1980s to mid-1990s.

Set 20 years in the future, criminals run amok and a gang called the Mutants terrorize Gotham City as superheros are a thing of the past. Bruce Wayne has been retired from crime fighting for ten years following the death of Jason Todd, the second Robin. Despite Wayne's funding the rehabilitation of Harvey Dent (Two-Face), Dent returns to crime. Wayne dons the Batman costume again and apprehends Dent, but the populace debates whether Batman is a savior.

But with Nolan expected to return for a third chapter in the series, might/could Warner Bros also launch a secondary Batman film? This practice is common in the comic book industry, where top franchise characters usually have a few titles running simultaneously, in addition to the occasional one-shot mini-series/graphic novel... Also, is Zack Snyder the guy to bring The Dark Knight Returns to the big screen?