Just a rumor, but according to the Wall Street Journal, it looks like it.
"Warner is already in development on a sequel to "Man of Steel" and is expected to fast track that for release as soon as 2014, said knowledgeable people close to the studio. In addition, it has long been developing a "Justice League" team-up movie featuring characters such as the Flash and Wonder Woman that could come out as soon as 2015."
Thoughts? Too soon? Or just right? I don't think this looks good for MoS 2, but if it brings a matchup of a Justice League film vs an Avengers 2 film in 2015?!?!?! COUNT ME IN!!!!