The Rogue One panel at Star Wars Celebration offered a few details about the plan for the first in the series of stand-alone films.
Director Gareth Edwards revealed that Rogue One will tell the story of a rogue band of resistance fighters who devise a scheme to steal plans for the Death Star. Concept art was displayed, and a short teaser was shown (but not released). The film will be set between Episode III and Episode IV, "a little more towards IV," Edwards said.
Only one of the Rogue One cast members, Felicity Jones, has been announced to date (see "'Star Wars' Stand-Alone Casts Female Lead"). She will play a Rebel, the panel revealed.
Filming of Rogue One is set to begin this summer in London. It will release in theaters on December 16, 2016.
The three stand-alone films alternating with the films in the next Star Wars trilogy will be called the Star Wars Anthology Series, Lucasfilm CEO Kathleen Kennedy told the crowd.
The Force Awakens panel at Star Wars Celebration also had its share of revelations (see "'Force Awakens' Panel Reveals").

From Star Wars Celebration
Posted by Milton Griepp on April 20, 2015 @ 12:59 am CT

MORE COMICS
To Bring Marvel, Star Wars, Disney, and 20th Century Studios Comics to Webtoon Platform
August 13, 2025
The deal will bring comics from the Disney, Marvel, Star Wars, and 20th Century Studios brands to the Webtoon platform.
Pairing Neo-Gotham's Batman with Dakota City's Static
August 13, 2025
The series teams up Terry McGinnis, the Batman of Neo-Gotham, and Virgil Hawkins, Milestone’s Static.
MORE NEWS
For 'Cosmere Roleplaying Game'
August 13, 2025
Brotherwise Games will be launching the Cosmere Roleplaying Game: Stormlight series.
New Graphic Novel by Creators of 'Banned Book Club'
August 13, 2025
Kim Hyun Sook and Ryan Estrada, creators of the Eisner-nominated Banned Book Club, are back with a lighter take on rebellious teens, meddling elders, and Korean traditions.