With the Man of Steel spearheading a DC shared universe, we know that Batman Vs. Superman is currently in development, and now it's learned that more DC movie announcements are coming soon.
In an article at the NYTimes, it's mentioned that Warner Bros. CEO Kevin Tsujihara stated a new DC movie film series will be announced in the near future (probably Comic-Con), and that Justice League is expected to be a part of that.
The current rumor (from yours truly at Cosmic Book News) surrounding Batman Vs. Superman is that it will lead directly into Justice League.
We can also speculate a Wonder Woman movie is being planned as Gal Gadot signed a three-picture deal, which is known to include Batman Vs. Superman and thought to include Justice League and a standalone Wonder Woman movie.
Other potential movies would obviously be standalone Ben Affleck Batman movies, more Henry Cavill Superman movies and possibly a film for The Flash, which has been rumored for some time. Aquaman has been amongst the rumors as well.
One possibility is that Warner Bros. may be going the opposite approach that Marvel Studios went with. As Marvel Studios didn't have the X-Men or Spider-Man, they decided to build up their "B-characters" leading to The Avengers movie. As audiences are already familiar with Batman and Superman, Warner Bros. can introduce their "B-characters" in Batman Vs. Superman, have them appear in Justice League, and then spin the "B-character" movies out of Justice League. Look what The Avengers did for Iron Man 3 and Thor 2: each became a blockbuster following The Avengers, much more than their previous movies. Having Aquaman, Wonder Woman or The Flash preceding Justice League might not have as much of an impact compared to following the Justice League movie.