Donner was actually REMOVED from the original film and replaced by director Richard Lester, after Donner had a falling out with the producers who wanted to make the film campier. The film as it was seen up until now, included footage filmed by both Donner and Lester (the Lester scenes are noticible by the bulkiness of Reeves and the different haircut for Kidder).

A lot of footage went unused, particularly some Jor-El scenes from Brando (some of which I believe ended up being integrated into Superman Returns).

I’m really excited to see what Donner’s cut looks like, as he reshapes the film in a way closer to what he intended, without having the opportunity to film anything new.