i hate to say it but after the "planet of the symboites" series in spiderman (the entire EARTH gets infected with the symboit and carnage hits damn near galactus size) they kinda killed it with the spin offs.

Yeah, Marvel really got carried away with the whole symbiote thing back in the day. Now I don't think there are any of the original ones left (Venom left Eddie Brock for Mac Gargan/Scorpion, Carnage got ripped in half by Sentry, and all the others just kinda faded into the background)

Anyway, as for the movie, I did happen to read the novelization (because I'm impatient) and in that one, Venom's only in the last act of the story. But then, the novel of Superman Returns was pretty different (read: better) than the movie, so who knows.