The problem with Supes Return was it wasn't a new take on Superman, in that Lex Luthor was dumbed down as a villain to be nothing more than a real estate bag man. Since Superman is essentially invincible (besides kryptonite)...
Darkening Superman is just plain stupid. Batman is the dark one. Superman's struggles are more about the light: how does someone with godlike powers feign humanity without getting dragged into self-interest? Also, a little Americana wouldn't hurt, either. Truth, justice, the American Way. Superman might be jingoistic, but, daggone it, it is stellar jingo, by gum. A pure hero shouldn't ever be boring, and no movie should ever make me pine for Superman IV: The Quest for Peas, but "Returns" sho 'nuff did. Ashcan the soap opera, let Supes kickass, and then maybe, just maybe, the classic fistfight with Batman...