Variety has learned that the studio hired Will Beall to write the script. Beall wrote a few episodes of "Castle," but has since been hired to write "Gangster Squad," starring Sean Penn, Ryan Gosling, Josh Brolin, and Emma Stone, as well as "Lethal Weapon 5" and the upcoming "Logan's Run" remake.
It's possible that Christopher Nolan may step in as director or at least produce "Justice League of America," and Christian Bale has already expressed enthusiasm in returning as Batman. Henry Cavill is a fairly unknown actor, and so it's very likely he would play Superman again.
After "Justice League of America," the studio plans to release "The Flash," "Wonder Woman" and "Green Lantern 2." If that's really what ends up happening is anyone's guess, but Variety says that Marc Guggenheim and Michael Green (Green Lantern) are writing "The Flash" script for director Greg Berlanti, while another "Green Lantern" writer Michael Goldenberg was hired to writer "Wonder Woman."