The official website was updated recently with some information regarding the upcoming Persona 3 movie.
Title: Persona3 The Movie #1: The Spring of Birth
Director: Noriaki Akitaya (directed Bakuman anime)
Supervisor: Seiji Kishi (directing the Devil Survivor 2 anime)
Music: Shoji Meguro
Anime studio: AIC ASTA
Japanese release date: Fall 2013
The P3MC's official name is apparently Makoto Yuki. Igor will return (most likely with canned dialogue like in the P4 anime).