The new version of Unigine Heaven benchmark will be available with the release of fermi. They showed it running on fermi at their both at GDC, without fps counter of course. I didn't get anything concrete about the release for linux of Heaven. Though they did mention the drivers are better. Perhaps soon after fermi comes out we'll see it.
The amount of new stuff they added to Heaven 2.0 is pretty cool. Lots more tesellation, and a whole lot of new geometry.
Well from what I have heard (albeit not from the "horses mouth") it appears they have been waiting for a "certain spec to be ratified". Should see a release soon.