Every few months Namco Bandai is rolling out a new version of Gundam Musou in Japan. The PlayStation 3 version arrived in March 2007. In December 2007, Gundam Musou: International came out for the Xbox 360, which was essentially the same game with the English voiceovers as a bonus.
On February 28, Gundam Musou Special arrives on the PlayStation 2. The “Special” in the title refers to additional scenarios and new mobile suits not found in the PlayStation 3 or Xbox 360 releases. No screenshots of the PlayStation 2 version have been released yet and it will be interesting to see how Omega Force polishes the visuals. The way Namco Bandai is handling Gundam Musou I wouldn't be surprised to see a Gundam Musou for the PSP and Gundam Musou: Ultimate, a PlayStation 3 re-release with all of the bonus content, in the future.