In all honesty, I'm not sure why the ability of software to emulate a photograph/camera is so important?  You can find spectacular photos in something like Arizona Highways Magazine, or visit Utah's Canyon Lands National Monument -- terragen works pale in comparison to the real thing, or photos of the real thing.

I can show you photos of Navaho sandstone formations that are absolutely incredible.

Personally, I hope Vue 6 simply allows much more artistic control and stability, to allow one to create art, not simply emulate what nature has already done.