By the way, this is rather old but figured it should be there for the easters. It's regarding the Deux Ex's series by Square. One of the games has an easter egg regarding Final Fantasy wayyyy into the future from a poster. It's labeled as Final Fantasy XXVII.
Some people probably knew this, some people didn't (such as myself because I never played Deus Ex: Human Revolution or Deux Ex series for that matter.) - It's set as
"Final Fantasy XXVII revealed for 2027 release!"
But once more this is just an easter egg or portion of a small joke and the concept may not even be that anymore in art, but it does hint on FF's longevity in the future as a series which likely means that FF will be around for a long time by searching all over the net.