It has already been announced that the Star Wars Anthology movie Rogue One will be in theaters on December 16, 2016 and now our excitement in that fact has something to stay grounded in: filming begins in THREE WEEKS!
Lucasfilm President Kathleen Kennedy confirmed that very fact in the SDCC Star Wars panel when she was asked about the future of the Star Wars franchise.
Star Wars: Rogue One will take place between episodes III and IV and follows a group of rebels on a mission to steal the plans to the Death Star. Felicity Jones, Riz Ahmed, Diego Luna and Ben Mendelsohn will star in the movie and rumor has it Darth Vader and a certain Bounty Hunter may show up as well.
Source: Geek Tyrant