Since it was wet and cold outside, we stayed inside the store and watched Gotham Knight. By around the ten minute mark, they were giving out posters. It's a two-sided poster, one side being Batman and Harley Quinn on the promo images, and the other side being the Batman: Arkham City logo.
Speaking of giving out, I also got a code to redeem three free songs from the Arkham City soundtrack: "Shadow on the Run" by Black Rebel Motorcycle Club, "Deranged" by Coheed and Cambria, and "Oh, Stranger" by The Raveonettes. Quote to reveal, make a post when redeemed.