While some think MoS will lend itself to sequels, at this point it's equally possible that this will be a standalone film. Warners had the Superman films indefinitely shelved prior to the lawsuit and they're only making this film because of the lawsuit. This film will have an uphill climb at the box office with it's inevitable 200+ million budget and June box office outcomes on big budget films tend to be weak. A lukewarm box office result may not be enough to encourage Warner Bros to greenlight a Superman sequel. WB has a history of having huge financial expectations for films like these, EX: they invested 400+ Million (including advertising) on Green Lantern expecting huge returns. I really hope this film goes all out without intentionally trying to save stuff for sequels which may not happen. Because of the box office requirements and the lawsuit issues beyond 2013, it's possible the sequels could be headed for development hell.