As has been stated before, this is fake. The video you posted, OP, has been out for a while on top of that, quite a while actually. I remember it from many months back, at the very least(probably closer to ^).
While the video may say 'Gameplay footage is not final', it's clearly showing us what to look forward to(the official beta/trailer we got. As Xander mentioned, they're more than likely just going to smooth things out and probably fill in the scenery to give it more life, etc. Nothing as drastic as that first video.