Arkham Knight got an update today that has photo mode as well as allowing you to earn the Zur En Arrh skin by registering to their forums and posting. I tried to get it but I guess the servers are being hammered so it may take a little bit.

As for the photo mode, it's not the best but it's not terrible either.

The camera is somewhat locked to Batman(Although it does work with Batgirl and Harley Quinn) making angles a little tricky. For example he has a sizable hitbox making it hard to get a closeup shot on him.

It does offer some nice options for adjusting the lighting, exposure, focal distance, camera distance, borders, filters and such Though the focal distance seems to be broken as adjusting the range does very, very little until you hit a certain threshold.

Honestly I'm more excited for the Zur En Arrh skin more than anything, but it hasn't been given to me yet so I guess I've got time to kill.