I was reading through the fbx upload guide and noticed that one of the texture sockets in maya responds to a metalness map. I wonder if that means reflective materials are going to become possible in the future, since so far I am only seeing specular reflections.
We are working on them right now. A precise release date can't be shared at this time but 'environment maps' are on their way.
For what it is worth the metalness map affects the degree by which the color map tints or otherwise affects the color of the specular highlights on an object. A very bright / white metalness map will cause the specular highlights on the object to match the hue of the color map.
The roughness map which is imported by way of the specular color channel of the phong shader basically defines how reflective an object is. If the roughness map assigned to the object is very rough then it won't be very reflective (this would be a very bright image). If the object is smooth (this would be a dark roughness map) it should be reflective.