With the addition of a shadow render pass and a Depth TOP, shadows can be rendered in a scene. The Depth TOP creates a depth map from the perspective of a light, then the shadow render pass uses this information to render shadows. Only hard shadows can be created using this method.

The Phong MAT has some shadow parameters on its Advanced parameter page. Shadow Strength and Color for a material can be edited here.

Also see Rendering Shadows for tips and an example of these features.