I think the origin could easily be done in the opening credits. One thing about Superman is that he's almost universally known. Almost everyone on Earth knows his origin. That could quickly be wrapped up at the beginning, hopefully to John Williams score.
And then just get on with it, perhaps his first appearance in Metropolis. I thought Birthright covered this pretty well. As did JMS's Earth One. I wouldn't mind a combination of the two for the new film. Wasn't too big on Johns's Secret Origin though. His Brainiac miniseries did kick ass though.
Rather than a straight up origin flick that covers his arrival and life in Smallville, I wouldn't mind a modified or truncated origin that begins with his arrival in Metropolis, so that it can establish this film's takes on Clark, Lois, Perry, Jimmy, Lex, etc.