Final Fantasy Versus XIII was unveiled at E3 2006. The project suffered a problematic development and was re-announced as Final Fantasy XV time ago. Ten years after that initial announce, Final Fantasy XV could be available on June 1, 2016.

Amazon Japan dated FF XV on its product file:

FF XV Amazon 600x322 Final Fantasy XV could be available on June (Rumor) | VGLeaks 2.0

June could be feasible. Square will celebrate a special event for FF XV in March (likely the official release will be announced there). The company had shown some interest to launch the game in summer and probably, Final Fantasy XV will release simultaneously worldwide.

Thanks, NeoGAF.