Possible 12th Movie title

According to a Japanese blog, by someone who has seen Giratina and the Sky's Bouquet: Shaymin in advance, the 12th movie is called Dialga vs Palkia vs Giratina. It is unknown if this is true, but the blog owner states there is the 12th movie spoiler trailer at the end of the movie.

Giratina and the Sky's Bouquet: Shaymin will be premiering in Japanese theatres on July 19 in Japan.