The Nolan Batverse should not mix with Superman because its story ran its course without requiring alien intervention. For Superman to show up now, after such terrible losses inflicted by Al Ghul, Joker, Two Face, Bane, and Talia -- all mere mortals, for the most part -- reeks too much of deus ex machina. Where was Superman the whole time, well why didn't he help? Stuff like that. It's actually a shame that for as much money that Man of Steel has made so far, the studio feels that another solo sequel isn't the next action. They're going straight to pairing them up, while there is still so much more of this Superman's world to flesh out. I know the goal is a Justice League movie, but after the failure of Green Lantern, why do they have to pair the two strongest DC properties together? Why not use the strength of both characters to bolster lesser known League members who haven't had recent films? Pair Superman with Wonder Woman. Batman with The Flash. Stuff like that. No more Christian Bale, please. I don't want my Caped Crusader to sound worse than that lady on the smoking commercial who had her throat cut open and sounds like death warmed over, if it can be avoided. It can be.