The original Overlord was a flawed game with a subversively chewy center. The only thing Overlord II needs to deliver to outdo the original is some polish, which is something Joystiq can't really tell is present from messing around with a demo for 10 minutes. That doesn't mean they didn't like what they saw, it's simply noting that Overlord's flaws didn't become strikingly clear until later in the game.
The latest title has the same whimsical art style as the original, but this time magic is starting to disappear from the world. The Overlord will not only battle a comical version of the Roman empire (Asterix and Obelix fans will notice immediately), but will be an antihero to the loss of magic in the world.