This trailer shows off some of the Direct X9 specific effects possible in Valve's Source engine, the same engine used to power the upcoming Half-Life 2.
Specifically shown in this trailer:
High-dynamic range rendering (for rendering realistic outdoor scenes, produces glows and saturated colors in bright areas of the scene).
Bump-mapped characters (containing both diffuse + reflective bumpmapping, DX8 only has reflective bumpmapping).
File name: Source_HDR02.exe