And to answer the continuity question: I actually heard that Superman Returns takes continuity from Superman I and II, but not fully. I'm not sure what that means, but I guess in the Superman Returns world Superman did sleep with Lois, but this time she remembered. That is also why we can throw out III and IV in the continuity structure. I don't know what is up Singer's sleeve for the next film or what is going to be introduced in the Donner edit DVD, but it will all make sense some how.
I may be a geek, but I'm willing to over look some continuity problems to just enjoy the movie. Same with the up and coming Batman Begins 2 movie. Apparently the Joker is in the next film and the Burton film is going into the "whatever" pile along with Batman & Robin, Batman Forever, Sups III, IV, Supergirl, Star Trek V, Godfather III, Star Wars PT, Temple of Doom, Jurassic Park III, and whatever gives us headaches.