What they mean by volumetrics is that the light and fog/haze interacts more with the clouds than before. Also, you can clearly see the interaction with the rest of the scene. No landscape software that I know of has true volumetrics or voxels...I know Digital Natural Tools does but it's a plugin for LightWave, Maya and others and costs over 600$. I don't think they could add this feature in Vue and keep this price level since they require a LOT of power and tweaking. For example a simple scene with voxel storm clouds in LightWave requires over 6 hours to render when you activate all shading effects so imagine with the interaction of Vue's scenes! :) I do agree that using the term "volumetric" in many softwares is a bit confusing. Cheers!