Many thanks to @koh_0805 for the link!
Japanes website, CinemaToday, is reporting that the world premiere of 47 Ronin will be held in Japan on November 19. Keanu Reeves, Hiroyuki Sanada , Tadanobu Asano , Rinko Kikuchi , Kô Shibasaki, Jin Akanishi and director Carl Rinsch will attend. The press conference for the film will be held on November 18.
The article, which is in Japanese and translates well with the google translator, is here.