I was kind of shocked to read through this thread and see some of the hate that Birthright has garnered, and it almost hurts me. I was a late comer to Superman fandom, and the last medium I took to were comics. The first Superman graphic novel I read was Birthright, and it literally blew me away. I've read many, many since then (Superman and otherwise) and it remains to be my favorite graphic novel (tied with Watchmen). I thought Birthright nailed the character of nearly every person in the mythos. From the origins at Krypton to Luthor's plot, I thought it was great. I'll admit, it gets a little weaker towards the end. But the beginning, particularly Clark's adventures in Africa, was incredible. I think that aspect, Clark traveling the world before becoming Superman, should be incorporated to every story from now on.
I'm going to confront a the common arguments against Birthright.
The aptly named "soul vision:" This really didn't bother me. All it really did was broaden the spectrum of light that Superman can see, which makes sense. Since the introduction of Superman's 'X-ray' vision, a lot has been learned about light and it's properties. It's okay that they've broadened that a little. This vision is really only an emission of light that living beings emit. This doesn't take anything away from the character, it doesn't really make him more powerful, and it gives an explanation for his devotion to preserve life. Sure, it's a little Zen, but it's not nearly a big of deal as people are making it to be.
Lex at Smallville in high school: I might be a little biased since one of my earliest exposures to Superman was Smallville, and I got used to the idea quickly. I can kind of understand why some people don't like this, but I really like how it was handled in Birthright. It takes nothing away from Clark and adds a little bit too Lex. Overall, not worth the hatred it's getting. In a movie, it certainly does not have to be included. But it didn't make Birthright bad.
I'd say those are the big ones. And I think a lot of it could be included in a movie. I think there would have to be a superpowered being included/instead of the fake Kryptonian army (Metallo Parasite and the like), but the story could work. One thing Birthright did that I think is important is that Superman was not immediately embraced, he was feared. That, I think is crucial, because if something like that happened today, if a man flew through New York City, people would be absolutely terrified.
I think if you took Birthright along with some of the other stories mentioned, we'd have a great origin. I find "For All Seasons" to be a little overrated. I really don't like the artwork, and it had some great stuff. I find it had great moments (Clark after the tornado with the preacher is perfect), while Birthright had a better cohesive story.
Bottom line, Birthright was great, and it could be used for a movie.