Quote from von*ferretmodels have always given off stencil shadows.
Nope, HL2 models use projection maps for shadows. One of the ways they get the sometimes rather complicated shadowing going without a too big performance hit.
Quote from skdrAren't these stencil shadows? If yes, they're new to Source tech.
Nope, that is selfshadowing which is demonstrated there and yep it's new.
Quote from SindwillerMaybe Valve has cuttet some ray-traced movies in, you know?
Nope, Valve have never used ray traced movies in any of the HL games, so I really doubt that.