Codemaster confirmed Overlord II overnight, this IGN report telling that the Triumph Studios-developed game will release in 2009 for 360, PS3 and PC.
From the piece:
Overlord II, "massively increases the scope of the original concept," according to Lennart Sas, director and Overlord lead at Triumph Studios. The game introduces a new Overlord, hinted at in the final scene of Overlord: Raising Hell, for a clash between him and a Roman-inspired empire which has plans to root out all magic and take over the world. The game moves beyond the fantasy realm of the first to something closer to our own, allowing the game's humor and satire to hit closer to home. Politics, environmental issues and more are up for parody in this game, though we wouldn't be surprised if a fart joke or two slip in.