I think it was originally that he catches the Hackensack-missile and takes it into space and lets it go. The San Andreas Fault-missile hits and Superman does his thing: lifting the plates, saving the bus, etc., including saving Lois from being suffocated by the dirt. The missile-in-space explodes and breaks the Phantom Zone portal releasing the Zod Crew.
We're then told that Superman will return next year (or something like that).