Nice interview on Newsarama. http://www.newsarama.com/movies/Superman/SuperWriters.html Basically this is a sequel to Superman I & II. At the end of Superman II, Sups tells the President, "Sorry to disappoint you, I won't let you down again", because he was not there when Zod invaded Earth. So then he promptly goes off into space for a few years? This doesn't really make sense.
(edited by kentish on 16.5.06 0948) Baby, you've got a stew goin'!
If you pretend the machine in Superman III is proto-Brainiac, it makes for a more enjoyable movie. Ok, no it doesn't, but its at least something. Superman IV was supposed to have Reeves as Bizzaro, but they didn't have the money to do it.