I thought I should make a thread about this, since Hitsugaya is my favorite character and he's the main guy in this movie. We're also going to get 23 pages of him in Bleach 304.
So from what I know, the movie is all about Hitsugaya. It talks about when Hitsugaya first went to Shinigami school, he was the youngest and he made a friend there, who is turns out to be the villain in this movie. We finally get to see how Hitsugaya became a captain.
I also heard that since Hitsugaya is young, his bankai is still developing and we might see some new attacks from him in this movie.