I think the next Superman film should be essentially the Superman version of Batman '89. In the '89 Batman film, Bruce has been The Dark Knight for quite a while but gothamites aren't sure that he actually exists. It should be the same for the sixth Superman film. Clark has been The Man of Steel for a while but he rescues people so quickly and flys away so fast that Metropolitans barely catch a glimpse of him and thus they're not sure that he actually exists because what happened to them was too unbelievable.

That probably sounds like a lame idea to you, but I don't care. My ideas will never see the light of day anyway.