Yes, it is real. Versus XIII was announced the same time as XIII though meant to be the PS3 exclusive for all the fans that felt that the 360 was some sort of blasphemy. We have heard next to nothing on the game since then, but now SquareEnix has released some gameplay footage. This should help to grow the hype machine once more for the Final Fantasy brand.
The video is pretty shaky and of poor quality but since it is not even supposed to be on the Internet, it is the best we could get.
In case you haven’t seen yet, the Extended trailer for the Versus XIII: