I guess Superman's 'S' could have stood for 'Serious, You Guys' instead of 'Hope'
It's a good thing the sigil for the House of El didn't look like a smiley face, or "LOL", or something like that.
We must always be careful to avoid reading too much good or bad into a trailer, or even a series of them, of course. Lord knows I'm trying to be a good sport about that "Elysium" trailer. (Vindicate my indulgence, Blomkamp!) I don't get quite the same "gloomy" vibe you're picking up, at least not to that degree, beyond the muted color scheme and effort to make Superman's costume look like a spacesuit, or armor, or something other than a brightly-colored costume. That's a defensible creative decision, although it's obviously your right to decide it doesn't work for you. His official look in the comics has changed, too:
On the plus side, the comics' efforts to explain why our hero's brightly painted long johns aren't instantly shredded by any attack that could even mildly inconvenience him - or, for that matter, the friction created by his flight speed - have always been strained. (He's supposed to be radiating some kind of incredibly thin force field that protects only his clothing, which gives artists the license to draw his cape all shredded if he's having a really bad day.) Changing his costume into a super-tough or regenerating suit of Kryptonian armor could be a somewhat milder strain on the suspension of disbelief from some audience members. Personally, I'm easy, as long as the story is working.
On the down side, Superman was originally rendered as a sort of living American flag, and any time the bright colors get toned down, I think back to that dreadful Superman Returns borefest and "Truth, justice... all that stuff" or whatever Perry White said.
But we can't truly judge the tone of the film by its color scheme, or its music. I haven't found the overall tone moody or oh-God-the-world-hates-me emo like Superman Returns. It seems more reverent, and filled with grandeur, as befits not only the most powerful man on Earth, but also one of American pop culture's most enduring icons. I don't get the impression Superman will be spending time floating around the Earth in a crucifixion pose, like poor Brandon Routh was made to do. As Costner's Pa Kent points out in the trailer, in this story Superman is not only an amazingly powerful hero performing wonders for the benefit of mankind, but also our first contact with an extraterrestrial species. A sense of wonder and awe seems appropriate, including from Clark Kent himself.
The notion of Jor-El sending his son to Earth as a messiah is not only not new, but it's been part of the Superman mythology from the beginning. It's not coincidental that Kryptonian names resemble the names of angels. In the Christopher Reeve Superman, Marlon Brando's Jor-El speaks at great length on this point - in fact, most of his dialogue (he was considered absurdly overpaid per word at the time) is about Kal-El's destiny as a savior and helper. "They can be a great people, Kal-El. They wish to be. They only lack the light to show the way. For this reason above all, their capacity for good, I have sent them you... my only son."
Good point about the foreboding mountains of Kansas, but I watched enough of Smallville to have grown accustomed to bizarre distortions of geography occurring around that tiny farm town. Hey, did you guys ever notice that you can see freaking Metropolis from the walkway around our water tower...?
I'll throw my geek cards on the table: I love Superman, always have, and have never considered him a boring character, except in the hands of bad writers. I'll (hopefully) live to see him turn a hundred years old, and he'll still seem fresh in the right storytelling hands. Part of that is because there are so many different ways to approach him. Even within the context of his world, he means different things to different people; he is many different things, more so than most other comic-book superheroes. He's an alien, the last son of Krypton. He's the most powerful man in the world, the hero other superheroes look up to. He's a guy trying to salvage a normal life despite a profoundly abnormal destiny. He's the selfless champion of everyone who needs help, no questions asked. He's a kid from Kansas who reveres his dear old Ma and Pa. And he's something far too many bad writers with pinched P.C. noses have been trying to take away from him: a quintessential symbol of America, embodying our strength, generosity, courage, and yes, hope.
Frank Miller at his peak was a grand master of visual storytelling, but one of my favorite Superman moments comes courtesy of Alan Moore. Supes has just fought a grueling battle against Swamp Thing, who nearly kills him. When it's over, Swamp Thing asks why Superman fights so hard for people who often treat him badly - not only had the story been full of various people hassling both Superman and Clark Kent, but he was protecting none other than Lex Luthor from Swamp Thing's wrath. Superman uses his super-hearing to listen to people across the city gossiping about him for a moment, often in cruel or foolish ways, then smiles and says with that whole-grain Kansas sincerity: "Because I love them."
Let me see if Zack Snyder gets that part right before I pass judgment on his take on the Man of Steel.
As for turning Green Lantern into a CGI Christmas tree ornament: totally agree. And if you're going to make a movie about space cops, give us the damn space cops, not a cookie-cutter superhero film featuring a guy who probably keeps his locker filled with Axe deodorant and back issues of Maxim.