A lot of websites have a stub entry for it, but no real information. Some list the release date as TBA and some list it as having passed. I can't even find anything on the company supposedly behind it (Begat). The first info about the game appearing around April 1st is also suspect.
Edit: Just found a press release: http://www.free-press-release.com/news-final-saga-the-gaia-cross-chonicles-officially-anounced-for-xbox-live-indie-games-1270229088.html which links to http://finalsaga.net/. So I guess it's real, but still not much info about it.