Personally, I think they 'almost' had the right idea last time, but executed it terribly. Superman is simply too overpowered to make him interesting in conventional terms, OR in 'edgy noir' terms (though, keep in mind that the original black-and-white and VERY successful Superman TV series was essentially a 'detective noir', where hard-nosed reporter Clark Kent tracked down the mysterious villain and then just turned into Superman when he worked out who the bad guy was and took him down in the end of the episode).
The only angle I can see that makes Superman at all interesting is to play UP the overpoweredness and the alienness. Make him the loneliest guy on earth - a beacon of light and hope and justice defending a world that repeatedly just doesn't seem worthy of it. That can be the difference between him and Batman - Batman is down in the gutter duking out, with an oh-so-thin line between him and the villains, Superman is up above it all, capable of taking down almost anything, but unlike Batman he has no reason to - these ant-like villains on Earth aren't anything to him, why should he even interfere?
They actually did that to a small extent in the first Superman movie (which seems ultra-cheesy now, but at the time was viewed as awesome - not quite KNEEL BEFORE ZOD!! awesome - but good nonetheless): when Superman (as Clark) first meets Louis she makes fun of him in an ordinary joking way, and he struggles to hide his astonishment, commenting 'why would anyone be deliberately cruel to another person?' or words to that effect. It's a nice moment, and sets up a certain loneliness in an film that was still very light-and-hope - if Superman is going to be so all-powerful that people are like ants, and so incorruptible that he's incapable of evil, the price he has to pay is that he can't ever fully understand the people he's protecting, who ARE capable of evil, even when they're mostly good.
It wouldn't exactly be a complete break from Superman continuity. It's always been there, and played up especially by the better writers over the years. Come-on, his base is the freaken FORTRESS OF SOLITUDE. The 'I'm up above it all, and just can't understand these people I'm protecting' is a running theme during Superman.
Oh, and if you want to see an awesome Superman story - check out 'Whatever Happened to the Man of Tomorrow?' - they got Alan Moore (you know, the guy that did a couple of minor comics called the Watchmen, V for Vendetta....) to do a proper finale for the Superman of the 70s and 80s, before they rebooted him again. Not at all suitable for a movie - it's clearly a sendoff, set 10 years after most of the super-villains have been defeated or retired, and then turns into an 'every major Superman character you can think of' comic - normally that guarantees an awful storyline, but somehow Moore manages to make a storyline with Bizarro, Metallo (those two only briefly), Braniac, the League of Supervillains, good-from-the-future-Braniac-5, Luthor, Mxyzptlk, super-powered Jimmy Olsen and Lana Lang work. And a large part of it is playing up the fact that Superman essentially lives alone with only a couple of friends that come close to understanding him...and what happens when certain super-villains kill those friends....(Moore doesn't hold back on the 'Superman is near-invincible, but his friends that put themselves at risk through their devotion to him are VERY mortal' theme).
Alan Moore is one of those writers that ruins comic books. Because once you've read Watchmen and V for Vendetta you realise that there just isn't going to be any other comics out there that will live up to them. Whatever Happened to the Man of Tomorrow isn't quite up there with those - he isn't Moore's own character, and Moore has always preferred anti-heros (notice how despite Moore being a political socialist, all his heros are right-wing Ayn Randists, borderline fascists or ultra-individualist-anarchists?). But it's an Alan Moore comic nonetheless, and you couldn't wish for a better writer to do a Superman finale.
