I just installed and did a quick run before I have to go.
With normal tessellation, on my 5870's in CF, I never saw below 40 FPS. It ran really well, however, there seemed to be a bit of white outlines at the joints between the legs and body of the dragon. Overall, it ran much faster than before.
I then tried to run it at extreme tessellation. At this setting, it would run 30-40 fps, except where there was cobblestone. With Cobblestone, it felt like a slide show, doing 20-25 fps. This option must be meant for Fermi to show off it's abilities. I didn't see any noticable appearance difference between the two, so I don't think I'll be missing a lot.
There is also a couple lower settings, so even the 5770's can handle some tessellation. I like this approach, to offer different levels of tessellation. The differences between the levels are not likely to look big, from what I saw, and it offers everyone a chance to see it, if they have the hardware. This should be how future games handle tessellation in my opinion.
After doing a few complete runs, it appears that the new version has lowered the image quality. The textures seem to be very grainy at times, almost like static over the copper surfaces. There is also some holes in a few of the objects, particularly the dragon.
It does run a bit smoother than before on normal tessellation, but the rest of the changes seem to be in a negative light. Maybe it just needs some more tweaks.