Seeing the beautiful (and dangerous) computer generated world of Pandora made fans want to see more of the "Avatar" series. Creator James Cameron made an initial announcement that the sequel will see the light of day sometime on 2018, instead of 2017.
With the first movie being a box-office hit, it's no doubt that it will start getting sequels. According to Coming Soon, the first sequel has already planned on starting production early in 2017, with a release date of December 2018. Three other sequels are also planned for release for the same month on 2020, 2022, and 2023.
It was speculated that the second movie of the "Avatar" series actually gave way for "Star Wars Episode VIII" since release schedules have changed for Lucasfilms.
Variety also had director James Cameron explain why he's taking long on the sequels. He mentions that the "cadence" of a release pattern is very important, wanting them to be release "as close together as possible." The director wanted reassure fans that that they will strive to follow schedule as planned.
Aside from a new cast, the original cast from the first movie will be returning. Those who are confirmed to return are Sam Worthington, Zoe Saldana, Sigourney Weaver, and Stephen Lang. It is still unsure as to how Dr. Grace Augustine (played by Sigourney Weaver) and Colonel Miles Quaritch (played by Stephen Lang) will return in the sequel's plot, though.
Cameron also did hint the details of "Avatar 2's" plot to focus mainly on family, instead of struggling against the human invaders, as Jake Sully (Sam Worthington) and Neytiri (Zoe Saldana) strive to raise their children in the alien world.