@Sparks: is this the old corkscrew from forza 4?
Yes. They just added the runoff on the inside, but that's just changing the texture and properties of that area. They did the same with Road America and Circuit de Catalunya in Forza 4, adding a few missing tarmac runoffs.
I guess the reason you're asking these comes from the laserscanning debate. What you need to understand is that what laserscanning does is create a point cloud 3D modeling of the envinroment with a sub-inch accuracy, like this (I'm posting iRacing examples because we're talking about a racing game, but just search for "laserscan" on Google Images and you get the same result applied to buildings, cars, mountains, whatever...):
If they went back to laserscan the track, it would reflect all the changes done to it since 2005 that they aren't present in the game, and it would have the right camber and elevation changes, which doesn't (it's very obvious at the entrance of the Corkscrew). The conclusion I can draw from these Gamescom videos compared to how the track was in Forza 4 leads me to believe that they haven't laserscanned it, they just changed the ads in the billboards and bridges, and they added a couple of tarmac runoffs, something that doesn't need laserscanning at all (Forza 4 already did it for a couple of tracks as I said earlier).
