They've packed the DLC like an over-stuffed suitcase. Suitcase full of what? Clothes. Bat clothes. Clown clothes. Office attire. Ninja attire. Luchador de ropa. Why free? Monolith. They're good sports. Like football. Like football helmets. With bat ears. Yeah. That good.
Who gets the DLC? Everyone. When? That depends. 360? Got it. PS3? Different times for US and Europe. Same for PC. How to know? Click below. Check the forum. There's a post on the update and patch status. That is all.