If this video is real, it's spoiled one of Square-Enix's megaton announcements for E3. Some not-so-secret filming at a pre-E3 briefing appears to show previously-announced Final Fantasy Versus XIII has now become Final Fantasy XV. A full, numbered sequel. But that's not the only (potential) megaton it's dropping: It's only coming out on PS3 and Wii U in 2012 to celebrate the 25th Anniversary of the series. No Xbox 360.
What can we take from this? The game has been in development for some seven years already, having been announced at E3 2006 and is being produced by Square-Enix's 1st Production Department. We're looking at a AAA entry in the series, so perhaps it makes sense that it becomes a fully-numbered sequel - especially considering Square-Enix had complained about the cost of making full-scale entries for this generation of consoles. Why go through all that again from scratch when a title of this caliber is waiting in the wings?
But that also has large implications for the series. The game was a spin-off for a reason - it's an action-RPG, which isn't quite in keeping with the traditionally turn-based gameplay that Final Fantasy is known for.
Whether it all turns out to be real or not still hinges on next week's press conferences. But seeing as we've heard nothing about this change before now, it's either a pretty convincing fake, or one of the biggest leaked megatons of recent years. But for now, we'll have to add it to our E3 rumours page.