So Daniel Pohl has updated his ray-traced version of Quake Wars, with a link to an article here and also discussed here.And of course it has been slashdotted here.
It looks good, like all ray-tracing does. A couple things ray-tracing does real well, that polygon renderers can struggle with are:
3)water with refraction and reflection
4)glass with refraction and reflection
It is much easier to add these features to a ray-traced engine than a polygon engine. Reflections and refractions are just modifications to the path of a ray. Shadows are just another ray. Even collision detection, with some cleverness, can share work with the tracing for rendering.
Ray-tracing on LRB is going to be very interesting.