Valve have announced the Source Filmmaker, their tool for creating animated films in a very intuitive way.
Valve have created Expiration Date, a 15 minute animated short featuring all the Team Fortress characters.
Half-Life: The Downfall of Evolution - Trailers
Two trailers are out for Half-Life: The Downfall of Evolution, a fan-film taking place in Valve's Half-Life universe.
Portal 2 - Perpetual Testing Initiative
Valve are introducing the Perpetual Testing Initiative for Portal 2 with this new amusing trailer.