Bandai Namco have announced that One Piece: Great Pirate Colosseum and Dragon Ball Z: Extreme Butoden will be receiving updates in November that will be adding cross-game battle support.
This will allow players to fight characters from the other games. This means you could have battles such as Monkey D. Luffy vs Vegeta, or Trunks vs Nami.
One Piece: Great Pirate Colosseum will release in Japan on September 21.
