Originally unveiled all the way back in 2006, Versus XIII was in development for quite a long time.
It was to be part of a trio of games including Type-0 and Final Fantasy XIII that used the same theme, same world and the Fabula Nova Crystallis mythology. Type-0 went on to be a Japan-only title for the Playstation Portable while FFXIII spawned two sequels, FFXIII-2 and Lightning Returns (launching next February).
Versus XIII had the misfortune of lingering in limbo for the next few years since its announcement and nothing more was revealed beyond the occasional update and the one gameplay video.
But now Versus XIII is no more and has been renamed Final Fantasy XV. A trailer was shown at the conference with footage of fast-paced magic and shooter action as well as some new characters, including the protagonist Noctis Lucius Caeulum. FFXV will be exclusive to the PS4, but no released date has been set as of yet.