well, heaven 2.0 has a massive boost in performance on the dragon scene, but overall has more content and doesen't really get higher avg. FPS (although, to me it does feel a lot more smooth than 1.0 overall)
Nvidia, on the other hand, used version 1.1 in their benchmarks. It seemed like the content was pretty much the same as 1.0, but performance was probably improved over 1.0
The only question is, how much of an improvement? If the FPS improvement in the dragon scene with 1.1 is similair to the improvement in 2.0, tesselation performance is very similair between 5870 and Fermi and Nvidia has been been blowing a lot of hot air. I'm guessing Fermi will still have better tesselation performance on average (it better given that extra billion transistors), but I doubt it will be as huge as Nvidia has been hyping it up to be.