It's only on PS3, though
The Arkham series is no stranger to offering extra costumes, but this Knightfall skin -- which is exclusive to the PlayStation 3 version of Batman: Arkham Origins -- is so damn cool.
There's also the Classic TV Series character skin, which looks especially silly and out of place in the dark, serious world of Arkham Origins, and five bonus maps: two Combat, two Predator. I wouldn't worry so much about the extra challenge maps, as there's never really been a shortage of them in these games, but they are a nice bonus.
As for Origins itself, I'm cautiously optimistic. I got to try it earlier this year and while much of the combat and traversal is exactly what you'd expect coming off of Rocksteady's last two titles, the new detective elements seemed like a neat addition.
Batman: Arkham Origins PlayStation-Exclusive Knightfall Pack Detailed [PlayStation Blog]