Raytracing didn't show soft shadow in reflections, nor did it do any
derivative even. Added a basic version for it in raytracer now, still
needs improvement on heavily curved surfaces. But it's better!
Examples:
Glass sphere, mirror cube and sphere, look how it ignores bump and shadow
http://www.blender.org/bf/derivative256.png
in svn now:
http://www.blender.org/bf/derivative-svn.png