Here's a dedicated topic to talk about the movie. I'll try and keep this post updated with the most recent info!
Okay, so they're in the middle of filming now, and expecting a release in autumn 2014. "The story's setting has been moved from a Japanese house to an old school dormitory. In the story, Aya Tsukimori (Nakajō) becomes part of an ancient "cursed incantation" at a girls' high school dormitory. Michi Kazato (Morikawa) is a classmate who is pursuing the mysterious disappearances at the dormitory."
It sounds like the plot of the movie is going to be original, not based on any of the existing games in the series, and will be an adaptation of the novel which is going to be coming out in August 2014. I don't know about you guys, but I'm really excited to have character names already.
Update 13th June:
The official movie release date has been announced, so make sure to mark 26 September on your calendars! Some new promotional photos have also been released. In addition, when the tickets become available for pre-order on 28th June, anyone who books in advance will receive a clear image of the heroine of the next game for Wii U!
Update 27th June:
The first trailer for the movie has been released (text and voiceover translated here, and Famitsu posted another article with a new poster and information about the singer performing the themesong, JAMOSA.
Cinema Today article (Japanese)
Anime News Network article (English)