Considering the theme of the game is hacking, is it possible this 'leaked footage' has infact secretly come from Ubisoft to fuel the hype fire and warm up the fan community letting them think gameplay was unofficially streamed live.
Since the live feed is now offline, anyone who successfully recorded the footage will start to spread it about the net, apparently its about 22 mins long. A cat and mouse game will now begin between the footage sprouting up and being taken down.
Or, maybe Im just reading into this too much lol
EDIT: I have to say though, it does look very nice...
Ani. Gifs:
http://vk.com/wall-30743032_534?browse_images=1