The film, called THE LAST PHOTOGRAPH and to be directed by Dane Niels Arden Oplev (THE GIRL WITH THE DRAGON TATTOO), is a revenge story where Penn's character is a special ops soldier who goes to Afghanistan to get who murdered his brother's family. He contacts Bale's character, a photojournalist who took the picture that documented the event.
Considering Penn's acting career thus far, this sounds different for him, and I'd imagine Penn and Bale together will make for some pretty powerful moments on screen. Zack Snyder and Deborah Snyder are co-producers. It's a flat out genre film as described by the producers, and it sounds topical as well as thrilling.