This should be taken with a huge grain of salt but Heroic Hollywood (22:44 mark in the video) says that they have found the possible titles for Justice League: Part One and Justice League: Part Two.
The four possible titles are Justice League: United, Justice League: Angels and Demons, Justice League: Gods Among Us, and Justice League: Gods Among Men. For some of us that third title would be familiar from the Injustice: Gods Among Us video game and tie-in comic. That story line follows a Superman that goes crazy and takes over the world after the Joker kills Lois Lane and their unborn child. It splits the Justice League in half as people pick sides. There was a hint of this plot during the Nightmare sequence in Batman v Superman: Dawn of Justice and a corrupt Superman.
The video also reveals some more release dates for DC films, again these are rumors, which are October 2nd, 2020, April 16th, 2021, July 2nd, 2021, and November 5th, 2021.
Justice League: Part One film is currently filming and is due out November 17, 2017.
https://www.youtube.com/watch?v=vx8RDFknMEg
