It seems like a long-shot, I'd certainly like to see this in my lifetime, but I think it will take a huge investment before it becomes a usable product.
Some of the stuff on their website looks very gamesy, but the Unigine and GeoGlyph sites have some mind-blowing stuff -- especially
Unigine, where the intro images on their site are about the best renders I've ever seen in what is meant to be a real-time engine.
Some of the GeoGlyph stuff shows some scenery which would make New Zealand amazing. I'm sure that one day we'll have something like this in our sim, but I will have to take more care of myself, and see if I can survive another decade or two...