The guys behind most of the current Dynasty Warriors games at Koei, who made those ol' Berserk beat'em all games (like Sword of the Berserk: Gut's Rage on the Dreamcast), and the recent beat'em all adaptation of Hokuto No Ken running on the same DW engine (Fist of the North Star: Ken's Rage) will adapt yet another manga/anime series into a beat'em all title!
They seem to do these spinoffs running on the same engine from time to time.
Sometimes generic non-Dynasty Warriors games (like Warriors: Legends of Troy, or Bladestorm: The Hundred Years' War based on the 100 Years' War), other times anime-based titles.
This time it's One Piece's turn!
One Piece: Pirate Musou is the Japanese title of this game they will make for Namco Bandai this time around.
It looks like mindless fun!
I guess that's one One Piece game I might give a try! (like Dragon Ball, there's been dozen of those...)
Like fans noticed, it seems it will adapt some recent story arcs (as Berserk Millennium Falcon Arc: Chapter of the Holy Demon War did on the PS2), instead of a big recap (like Fist of the North Star: Ken's Rage) or an original story (like Sword of the Berserk: Gut's Rage ).
I'm guessing the title will be changed outside Japan, like Hokuto Musou became Ken's Rage.
One Piece: Luffy's Rage anyone? :B