I didn't click on the actual link in this thread, but where I read the news earlier today, someone (Snyder? Goyer?) said that while they won't do the "Returns" storyline, they may borrow parts like they did from 'Last Son' and 'Rebirth' when they scripted Man of Steel.
And the actual Dark Knight Returns came out in '85 or 86 I believe, and worked well because it occurred with the backdrop of the Cold War. Not sure if that would translate (ie. how they changed the Watchmen script).