But with Batman it's different. Only comics fans really know the ins and outs of his origin. Most folks just know his parents were killed, that made him angry, and so he dresses like a flying rodent and fights clowns and catwomen.
Not to mention Batman's life between 8 and coming back to Gotham at 25 has always been kinda vague. BB made a whole new story out of it. Whereas Superman's origin, everyone has seen it. And every one is basically the same. As good as birthright is, anyone who's seen Smallville and the Donner movie knows 75% of the story rght there. It's been done to death.
They certainly could do a lot worse, but I still say just go for a Incredible Hulk style reboot. Everyone knows who Superman is, what he's about, knows Lois Lane, Lex Luthor, Metropolis, etc...Just hit the ground running in the next movie. And make Braniac or Darkseid the villain so Supes will have things to do other than lifting heavy **** and flying around all lovey dovey with Lois....make it a big time action spectacle. The one thing we haven't gotten from a Superman movie yet, IMO. They've developed the characters till the cows came home and got sent off to the slaughter house. Now it's time for some payoff. Lets see some seriously kickass set pieces and super-powered fist fights!
The thing is, most people DON'T know Superman's origins. That's the biggest misconception I've heard around the internet. People don't know who "Kal El" and "Jor El" even are, even if they DID see Returns. I've been asked numerous times, "if Kryptonite is pieces from his home planet, why does it kill him?"
I usually respond by hitting these people in the face.
People know he's alien. They probably know his planet exploded. They may know about Smallville because they've heard about it.
Most people haven't seen the Donner Superman. Most people don't watch Smallville.
The same argument really could have been made for Batman. Your argument was that "the whole period from when Batman was 8 to when he was 25" had never been seen, which is true, but the same could be said for Superman. You have birth, smallville, Superman, typically. Donner's version conveniently 'skipped' this era as Clark was 'training' (a convention I hope is not repeated). But Birthright shows this era in one of the greatest Superman stories I've ever read. His experiences in Africa provide a great beginning to Superman.
Though, I'm not opposed to having a story that jumps right into it, where the characters are established. I'll say my pros and cons here, to using an origin story vs. jumping right in.
Pros:
-Shows Jor El and Lara, important pieces of Superman that people know squat about.
-Reestablishes Krypton, so it isn't a giant icicle.
-Gives the opportunity to introduce a Kryptonian villain(s) (Zod, Brainiac if you like TAS version) that can be used later (I'd prefer Brainiac)
-I want to see that Africa storyline on screen.
Cons:
-An origin story might cut back on action.
-It's hard to have an origin story without having Luthor as the main villain. Sure, he can be involved in a powerful villain (Metallo might be best), but people are still a little tired of Luthor's shennanigans.
-Darkseid/Brainiac might be too big to use in an origin story, and these two villains really need to be used at some point.
-While most people don't know, it will be somewhat rehashed to anyone who knows anything about Superman.
Honestly, I just WB to get their stuff together and deliver us the Superman movie we deserve. I enjoyed Returns, but it probably wasn't what we needed. (We needed an origin story then, to be honest). As long as it's a great Superman story, I won't mind whether it's origin or not. I agree he needs someone to fight, in a bad way. I've also heard people think that Lex is his only enemy. [sigh]....
Just give us a movie.