I don't know how true this is, but it's waaay too awesome to be done by anybody but Valve. A whole new concept, different from what we've seen so far.
Everything about this video can be described as excellent. The funny passcode, scout's butterfly knife-twirling, little action sequences featuring the spy at work (the way he saps the sentry is a bit OP, but it's all in the name of making the spy look cool), the Russell Peters tribute, and the awesome (yet somewhat expected) twist at the end.
Still, Valve has no confirmation that this is the official video.