I've seen Daegon Reiko Frost and Kenshi fighting in the background of the pit.
If they add Daegon instead of someone like Havik or Chameleon I'll be quite angryYep me too. I'm almost possible they're all going to be DLC. Just think about it. You can see Mileena's flesh pit costume when she is in one of the tanks in the Flesh Pit level. I've seen Skarlett chained up numerous times in the coliseum and she's confirmed DLC. There's hints everywhere.