Tron 3, which is rumored to be titled Tron Ascension, will indeed bring back Olivia Wilde as Quorra. She joins previously announced Tron: Legacy co-star Garrett Hedlund. Joseph Kosinski is also confirmed to be returning to direct this follow-up to his 2010 Disney sequel.
Tron: Legacy was the long-awaited continuation of the 1982 flop-turned-cult favorite Tron, which took its hero inside a computer world known as the Grid. Both the original and the sequel starred Jeff Bridges and Bruce Boxleitner, though neither actor is yet confirmed for this next movie. Tron: Legacy revealed that Jeff Bridges's character, computer programmer Kevin Flynn, had a son named Sam, played by Garrett Hedlund.
Sam jumps into the Grid to search for his long lost father. While there, he meets Olivia Wilde's character Quorra, an algorithm made flesh who escapes the world of the Grid at the end of Tron: Legacy and enters our reality. It's believed that the title Tron Ascension refers to her 'ascension' from virtual reality program to human being, and the story may see other iconic elements of the Grid world coming into our existence.
Disney has been developing a sequel to Tron: Legacy since that movie opened in 2010, with the hopes of starting a fresh franchise. This was before Disney bought LucasFilm and began planning their mammoth new Star Wars franchise. Tron 3 will being shooting in the Fall, most likely in Vancouver, Canada. At this time, all official story details are being kept under lock and key.