From the video description:
4 Hunters stalk 1 giant Monster... but the beast lies in wait. Who is hunting who? Welcome to #4v1. Happy hunting. In a savage world of man vs nature, are you the hunter or the hunted?
NeoGAF user crazy buttocks on a train has come across what they claim is a confidential presentation from Valve showing images of Left 4 Dead 2 rebuilt in a new Source 2 engine. This long rumored new engine could be the basis for L4D3, so the internet has collectively worked itself into a frenzy of LFD3 rumors. Don't get too excited; we all know Valve can't count to three.
From Game Informer:
The sci-fi multiplayer-focused shooter pits a four-player crew of alien hunters against a separate player-controlled monster that grows larger and more powerful over the course of matches. Each hunter features its own unique items and abilities, and while the monster may be outnumbered, its size and an assortment of devastating attacks make it a more than formidable foe. Like Turtle Rock's previous titles, Evolve is being built with variety and replayabilty in mind; the result is a novel mix of cooperative and competitive multiplayer elements that's unlike anything we've played before. Our exclusive hands-on time with the game's four-versus-one hunt mode left us with plenty to be excited about, and you can get all the details in this month's issue.