So, DC Entertainment apparently is planning a Justice League movie - and it'll apparently feature versions of both Batman and Superman than are appearing in their own movies. Clearly, DC and Warner Bros are looking forward to seeing how quickly they can screw up their superhero franchises.
There are countless reasons why the idea of recasting not just Batman but Superman in any Justice League movie - never mind one that may be coming out just a year after the in-pre-production Superman reboot that Zack Snyder is currently working on - is a bad one, not least of which is that it's going to be confusing to audiences ("Wasn't some other guy Superman last year?"). But more than that, it's entirely unnecessary. Yes, I get that both Christian Bale and Henry Cavill may be too expensive by that point for what are likely to be, essentially, cameos in a movie dominated by other characters and actors, and so from that point, recasting makes a lot of sense. But... why do Superman and Batman even need to appear in the movie?
Follow my logic: For the majority of the Justice League's early years, both Superman and Batman were small presences in the story, probably following on from the similar role they played in the Justice Society stories of the 1940s and '50s. Although they are featured in the origin of the team, they're barely there, getting what amounts to a "And all of this happened off-panel" treatment compared with the full adventures of Aquaman, Green Lantern, Wonder Woman, Flash and Martian Manhunter in the same story. Although they are occasionally treated as the core of the team - Hi, Brad Meltzer! - there's actually little reason beyond name recognition that either character actually has to be in the movie.
Ah, you say, but isn't name recognition enough? Well... yes and no. Presumably, Ryan Reynolds' Green Lantern will be appearing in this movie, and he could really be enough of an anchor for most fans to want to see the movie (To put it in some perspective; Thor and Captain America: The First Avengers aren't out yet, but non-comic fans are still excited about The Avengers based solely on the example of the Iron Man movies). Batman, as movie audiences have gotten used to him, wouldn't even fit into the fantastic world of the Justice League, and Superman's power set could cause more problems than solutions when it comes to setting up a credible threat for the League to bring to Justice, so it arguably makes more sense not to include them.
(Using Wonder Woman, should her TV show be a hit, may cause similar problems. Do you bring Adrienne Palicki into the movie, and officially out that show into the movie continuity? And if so, what does that do to close down the scale of the show's plans?)
That said, name recognition isn't something to be sneezed at, and I'm sure the chance for DC and WB to play up the Superman and Batman brands - even as they undermine them with confusion over who plays those characters at any given time - will be too much to refuse. But, still. I can't help but feel that letting Superman and Batman join the Justice League will lead to the kind of disaster that the studio would need a superhero to save them from.