During the Aniplex Online convention, it was announced that Sword Art Online the Movie -Progressive- Aria of a Starless Night will be premiering in Japanese theaters on October 30!
As of now, all we have received is the release date and a piece of key art which you can check out below:
Sword Art Online Progressive is a light novel series by Reki Kawahara that revisits the original Aincrad arc, expanding on it as Kirito goes floor by floor. A television anime of Progressive was also announced previously but there is no release date for the show.
Source: Aniplex Online, SAO Twitter