Hot off the press, this sample provides handy classes for generating cubes, spheres, and teapots (great for debug rendering!) while this one shows how to do various hopefully useful things with skinned character models.
Notice how Skinned Model Extensions reuses code from the Primitives3D sample for drawing the collision spheres? You'd almost think Primitives3D was created because halfway through writing the skinning stuff I realized I had no way to display that data :-)