Next February, a new Code Geass anime feature will be released in Japanese movie theatres. It’s called Code Geass: Lelouch of the Re;surrection.
The movie takes place after Code Geass: Lelouch of the Resurrection R2, the second TV anime series. This one movie will serve as the conclusion.
Code Geass: Lelouch of the Rebellion debuted as an anime TV series in 2006. It was followed by Code Geass: Lelouch of the Rebellion R2 in 2008. I guess this movie is the default R3?
No word yet on an international release.