Meet the Heavy

From Valve:

We are pleased to announce that the next generation of facial animation technology for Source will be released in Team Fortress 2. By leveraging the rapid pace of advancement in PC graphics, video games can now match and actually surpass the facial animation used in feature film and broadcast television production. We've released a video of this real-time, in-game, in-engine facial animation in action in support of ATI's launch of the Radeon HD 2000 series. By running entirely on the GPU of the videocard, the facial animation not only looks dramatically better, but frees up the CPU to perform other tasks like physics or AI.

Watch the video