On the official Twitter account of the awaited Valkyria Chronicles 3 announced that a planned 2-episode OAV (Original Anime Video) has been planned to be released next Spring.
This trailer above is the trailer of the game which was first seen in the Tokyo Game Show.
Titled, Senjō no Valkyria 3 "Dare ga Tame no Jūyu," it was originally announced at a press conference on a Tuesday morning. In the said event, the game's full opening animation was screened for the first time and revealed that the singer May'n is perfoming the opening theme song. Finally, there will be Nendoroid figures of the characters Riela and Imca.
Source: Livedoor, Uri-Sure Matome R via ANN