One Piece: Pirate Warriors (surprise?) will have downloadable content and Jump has a scoop on the items. On March 1, fans will be able to download a warrior costume for Luffy. The armor is similar to samurai gear sans the helmet.
Nami will have a kimono costume available on March 8. Other characters will get DLC costumes too with details coming at a later date.
One Piece: Pirate Warriors comes out for PS3 on March 1.