Here is what my shader spits out (note: crumbs of breakfast not implemented)
There are two shaders there actually: a displacement shader and a surface shader. The wood surface is straight from the Renderman Companion.
Here's what it looks like with just the displacement shader:
Clearly that takes us most of the way there. And since that's all a displacement shader it should look realistic as the light moves around.
The surface shader gets us the flecks and the fringe:
The source code for the shader and scene: