StarCraft 2 Heart of the Swarm Video Leaked?

A video claiming to show the ending of StarCraft 2: Heart of the Swarm, the next title in the startegy series was leaked onto YouTube last night.
Activision are obviously not happy at the situation although it is still unclear as to whether this was a real video or a fan created piece of footage. The fact that Activision has been chasing around trying to get the leaked footage removed points to it being legitimate.
The video was also watermarked with the name of the production company who lists Blizzard as one of their clients so there is some good evidence to suggest the video was legitimate. The audio that is present is also very authentic so we think this leak could have some merit.
The video has now been removed from YouTube but you can view it below.