This Team Fortress fan animation created with Source Filmmaker is a cool tribute to the ZombiU CG trailer.
Valve have announced they will release their Source 2 engine for free to content developers.
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 - TV Spot
Valve has released a fun tv spot for thier upcoming game, Portal 2.