This is one of those funny things which makes the internet explode, until you realise that it's completely fake. At that point, everyone just looks stupid.

In short, a video was released on YouTube which showcased Final Fantasy Versus XIII footage, but had the Final Fantasy XV logo at the end. It looks very professional and isn't fake - in the sense that the video of the video is real. The footage itself is fake. However, the person who made the video works on a fansite called Final Fantasy Dream and made it as an entry into the "buzzies awards" at his University.

It stated that Versus XIII would be rebranded and that it would now be released on the PS3 and Nintendo Wii U.

If you want to check out the video for yourself, feel free - here's a link so you can watch it!