The Overlord franchise will also spawn Overlord Dark Legend on Wii by Climax Studios, an "all new game" penned by Rhianna Pratchett. The game seems to be set in the original Overlord's world with many of the same characters, but with the inclusion of some fractured fairy tale aspect. Finally, on DS (and also by Climax Studios), Overlord Minion will present players with a puzzle action game. OK, does that about cover all the Overlord info? Good, all hail the Overlord!
Source -- Overlord 2: Xbox 360, PS3, PC
Source -- Overlord Dark Legend: Wii
Source -- Overlord Minion: DS