Injustice: Gods Among Us was rumoured to include characters Killer Frost and Ares recently, but an image from Warner Bros. employee Brandon Alexander confirms that yes, they’re in there.
Joystiq has the image here. It was tweeted but now the tweet in question has been pulled. Oops.
We got our first hint of the pair being in the game after some related avatar items popped up on the Xbox Live store. Check them out here.