Despite a few boisterous detractors, Zack Snyder's unique vision for Superman in Man of Steel  generally mollified wary comic book fans and casual moviegoers alike. Sadly, that same can't be said for Batman v Superman: Dawn of Justice. With the majority of the audience left wanting more from the film, many comic book fans were hoping that Snyder would be given his walking papers after Justice League (if not before). Well, it appears that won't be the case as Snyder told the crowd of bloggers during the JL set visit that he's working on a secret project with Geoff Johns.

JoBlo.com reports:

“Geoff Johns becomes the topic of conversation as Zack shows his admiration for his work and comic-book world knowledge. Zack also mentions an upcoming project that they’ll be working on but wasn’t allowed to discuss further with us.”

Is it another movie in the DC Films slate? That's the most likely answer, though there's also the possibility that Snyder could be working
Source: COMIC BOOK MOVIES