I don't, somehow, think that's 1.3. For one, if you compare the aura used in the video to the ones that were recently featured in the POTW (or even to the one in older POTW's), it's a bit different. That's the first tip-off I saw. Also, I don't ever remember a video like that making it to the main page...and if the team didn't release that video...
If I had to guess, I'd say it was using some custom models, sprites, sounds, etc., but is still the same 1.2 you know and love.