Xi is done; it's finished. The alternative reality game found within PlayStation Home is now complete with an ending. Some of you may have already discovered the super secret finish to Xi, but some of you haven't yet. This doesn't mean those of you who haven't won't ever get to -- there's still time.
As detailed by the PlayStation Blog, all Xi-related spaces in Home will still remain active "for a few weeks." It looks like all you latecomers have some time to catch up. So get out there and start searching!