The Prinny team aren’t making another game with the peg-legged penguin right now. They are in charge of Nippon Ichi’s next major franchise The Witch and the Hundred Cavalrymen. The witch in the title is Metallica and the "Hundred Calvarymen" is actually the player character.
You control Hyakukihei who is summoned by Metallica and is the only unit out of the cavalry with a fixed form. Hyakukihei (or whatever you decide to name him) doesn’t live by a moral code. Dengeki Online explains that residents like a strange fishman will offer side quests. You can fulfill requests, backstab them by doing the opposite or even attack the quest giver.
Usually, Hyakukihei has to fight monsters on his own, but…
… he can temporarily call out the other 99 soldiers for support. In the screenshot below, two units are attacking a monster.
The Witch and the Hundred Cavalrymen is slated for release in spring 2012 for PlayStation 3.