This comment section has been very intersting.
I disagree with some of it, though. Long post incoming:
For example: DC does care what the fans think - but that's a bad thing!
Think about it: No-one here wants to see the clichee "they fight each other, they make up, they team up, they fight crime" formula. It has been done to death.
Yet, why would WB go into that direction? Because X vs. X is a traditional fan topic. When you talk to comic fans it's one of 5 topics: What superpowers would you want? How stupid/hot/impractical is X's costume? What would have been your version of X event/how could X event be improved? DC vs. Marvel - which leads you to who would win in a fight X vs. X?
So, with a fan culture like that - why would WB bet the farm on a buddy cop movie, or do anything else than what the fans obviously want to see? If they check out this comment section - we have, so far, bitched about MoS, and discussed the topic of X vs. X - even though we all agree that we have no solid indicator that they will even fight, and we all agree that the basic X fights X formula is a terrible idea.
We hate the idea - yet, everyone wants to talk about just that. Why would they make another movie?
Also Dark Knight Returns is a pretty awesome comic.
I had a class last semester, in which we read and analysed it, and there's a lot of thought behind the surface.
So I really disagree with Raika, who said that:
Batman: The Dark Knight Returns is, was when it came out, and always will be absolutely fucking terrible. Frank Miller can't write his way out of a shoebox and it's painfully apparent in that story in particular. It's infantile, nihilistic trash for teenagers who want to feel "hardcore". That's all it'll ever be, and pretty much nothing good can come of a movie taking hints from that, especially since Man of Steel completely missed the point of Superman as a character to begin with.
Well, I'll admit DKR has some real problems: Batman using guns, killing people, rolling on people with a tank ("Rubber bullets! Promise." <- rubber bullets, my ass!).
In a way, there is some fundamental misunderstanding of Batman in DKR, just as with Superman in MoS.
However, in DKR, Supes and Bats have the exactly right positions within society: Superman is working with and for the government, while Batman works from the shadows and is a thorn in the governments side.
The point is raised that Batman, by operating outside the law, and by using unsanctioned violence, while being not accountable, inspires all these crazy madmen, gives them something to work against.
It's no coincidence that they have a pro-Superman, anti-Batman psychologist running around.
Batman is so good at what he does because he does it without the whole bureaucracy - he goes where he needs to go to collect his evidence. The problem is that, because the system is faulty and the Joker is set free by some celebrity psychologist, Batman is needed. The POTUS even wants to give him a medal.
But he inspires all the crazy people, who are drawn to the unsanctioned violence Batman uses: Think of the Sons of Batman (previously Mutant gang members, who "convert" to Batman-ism after Bats beats their boss), and how they just straight up mob-murder people for stealing handbags.
Superman is not "corrupt" in DKR - he just choses to act with force (=violence) sanctioned by the official government. He works from within the system, still having faith that it ought to work. Which is, of course, why he gets hit in the face with a tactical nuclear warhead.
I'd argue that makes him see Batman's point, in the end. Superman's silence, as he discovers Batman's ultimate trick, can be read as silent approval: Supes freaking GETS IT now. The system is not perfect. Better to have a Batman around in the shadows should you ever need him.
Coming back to an earlier point: DKR would have never been made had Miller listened to the fanboys.
DKR is what is called a "revisionary narrative" - meaning that after DKR's version of Batman you couldn't go back to the old version. Adam West's Batman got overwritten by the new, gritty, grim Batman.
Example: For all of Batman's history, the yellow symbol on his chest was just .... well, because! Because superheroes have symbols on their chests. Because yellow makes the black bat symbol pop.
DKR >explains< the symbol for the first time! It's a deliberate target, painted on Batman's chest so villains will shoot his chest. The only other bright spot on the costume is Batman's lower face, which would be the first thing bad guys see and shoot at instead. So he gives them a better target. He can armor his chest. He can't armor his face.
And because DKR has this >explanatory power< it convinces us more than all earlier versions. We can never think away that explanation, so it replaces the old, inferior explanations, versions and instances.
These are not my ideas, btw, as I said: I had a class. If you're interested go look up my two main guys:
McCloud's "Understanding Comics" and Klock's "How to read Superhero comics and why".
It's theoretical stuff, literary analysis - but in the very least you're gonna get some awesome comic tipps, from literary experts, who name-drop you the industry's best as secondary sources :D
I had a ball reading those texts because some freaking phd was ratteling down a list of very good comics - and I had read them all!
And sorry for the wall of text. I needed to vent information.