"Batman: Arkham Asylum" had a fair amount of references to classic franchise villains, but in terms of the actual villains you got to punch in the face in that game, there were only around 4 or 5. "Batman: Arkham City" seems to be rectifying this problem with an appearance by more major villains that one would think possible in a single game. So far we've seen Two Face, The Joker, Harley Quinn, the Riddler and Catwoman, but today adds three more to that list. You can see two of them, Penguin and Solomon Grundy, in the trailer up top.
Penguin has gone through plenty of changes throughout the years. Rockstead's Penguin appears to be a grenade launcher-loving cockney with a high tech monocle. It works incredibly well, especially when seeing him in his natural habitat, the Iceberg Lounge.
Hiding in the depths of the lounge is one of the lesser known Batman villains, Solomon Grundy. In the DC universe, Grundy is an undead merchant from the 19th century who comes back to life to give Batman a hard time. He's big and hulking and will likely take the place of Bane, who got pretty worked over in the last game. But, who knows, we could see Bane and Grundy fighting Batman at once.

If those two weren't enough, EW is confirming that Talia al Ghul, daughter of the ever-living Ras, will be in the game as well. She'll be played by Stana Katic, the female lead of ABC's "Castle."
It seems unlikely that Rocksteady would reveal every last villain that will appear in "Batman: Arkham City" before it launches in October, but even if the list stands at its current eight, that's a pretty sizable increase from the first game. On the other hand, we still don't know if Scarecrow's making a return. Some things are better left as secrets.