There are a lot of rumors on the internet; people print any old shit because it gets hits. If you're interested in rumors that have some credibility, you only listen to a handful of people on line. One of them is Drew McWeeny, formerly of Ain't It Cool and now at HitFix. I'm not saying Drew is always right, but he's careful, and if he runs a rumor it's because he has a reasonable sense that it's true.
That's all prelude to this:
According to Drew, Joseph Gordon-Levitt will be playing Batman in Justice League. You'll remember that his character, John Robin (ugh) Blake, inherited the mantle of Batman at the end of The Dark Knight Rises. At the time it was unsure what would happen; I had sources who told me that JGL had not signed an iron-clad contract and that everything was up in the air when it came to future Bat films. That source seems to be in line with what Drew says, as HitFix reports that Warner Bros is signing deals right now to secure JGL for Justice League.
And maybe something more. The biggest bit of news that Drew drops - and this is possibly a spoiler for people who care about this sort of stuff - is that WB is trying to get JGL into The Man of Steel. The film is finished shooting, but as Marvel's cameos have shown us, stuff can be inserted at the last minute. Zack Snyder has recently said his Superman movie is a stepping stone for Justice League, and having Batman show up at the end - Nick Fury style - would make sense.
It would make sense in general for Warner Bros to ape Marvel's style. That tease/cameo system has proven to work well, and Warner Bros doesn't seem to have a clue what to do on their own.
For me this all raises larger, nerdier questions: what is Joseph Gordon-Levitt's Batman like? He's not as gruff and tough as previous iterations, that's for sure. He's not as screwed up and angry, either. A Blake Batman interacting with the Justice League is way different from a Wayne Batman doing the same. I suppose they could write Blake to be Wayne II, but in a lot of ways that counteracts the whole point of Blake - a saner, more centered guy - taking on the cowl.
Of course all of this could end up being untrue, or could be the sort of thing that's true today and not tomorrow (ie, deals don't get made). But Warner Bros is rushing forward to get Justice League in theaters by 2015, so I'm assuming they're very advanced in negotiations.