Just in case you were worried that Final Fantasy XI going online would bring about the end of the beloved series, fret not, for it appears that Square has no intentions of letting it's beloved series end with their first completely online venture. At least that's the way it seems right now.
On February 10th, Square registered a few website domain names. This might not seem like such a big deal, as domain names are registered all of the time. However, the domain names that were registered were not for any game Square had announced. The domains they registered were for Final Fantasy XII through Final Fantasy XV. Yes, that's right, the 12th through 15th in the series. The specific names registered are as follows:
Keep in mind that this is in no way a confirmation that these games are in development, much less even in pre-production. This is most likely an early step at protecting the sites for future use, should they decide to make the games, which seems inevitable in light of the recent Square Millennium conference. In other words, don't get too excited yet. Square still has to get through Final Fantasy IX, X, and XI before they can get to this bunch.