http://www.ign.com/articles/2013/01/30/injustice-gods-among-us-the-death-of-metropolis
The "build" featured in that and many other publications about a month ago says Hawk Girl, Aquaman, Doomsday, Raven, Ares, Bane, Shazam, Black Adam, and Sinestro all turn up in a superfight within the first chapter of the story mode. Before that, only Bane was confirmed but since then we have seen Shazam, Sinestro, Aquaman, Doomsday, and Hawkgirl have all turned up in gameplay. So I'm just gonna go ahead and say Raven and Ares are too, with none of that costume only nonsense.
My list looks like this:
Supes - Lex
Bat - Joker
WW - Ares
Arrow - Deathstroke
Lantern - Sinestro
Shazam - Adam
Flash - Cold
I'm assuming they will line up Bane, Cat, Harley, Grundy, Cyborg, Nightwing, Hawkgirl, and Raven in whatever way the plot needs, leaving Aquaman the only character still in need of a counterpart. Doomsday could be the Goro, and whoever makes everybody a god and freezes the world can be the Shao Kahn.