The shadow is very well done. A catchlight in the surface of the coffee would have been nice. The faint color shadows along the bottom edge are a little distracting. Since they seem to be mostly green/yellow you might have been able to remove them with selective desaturation.
i like the idea for this photo! i would be interested in seeing how this image would look with a deeper (more visible) shadow tone and a less-bright background.
Simple and effective. The shadow is especially significant as it should be denser nearer to the cup yet that's where it bleaches out. The result is an art feel rather than a photographic treatment. Very well done