Standard (Specular setup) shader with black specular still have specular color rendered. I'm not sure is it intended (because of new physic based shading), but as I understand specular setup is more like artificial specularity suppose to be.

1. Open scene "Test scene".
2. Select material "mat_test".
3. Notice that specular color is black and gloss is zero.
However cube is not completely black.

Reproduced: 5.0.1p3