I will buy this game on launch, I may even consider pulling a sickie on release for this title! The "proper" (not concept or prologues) games that have come out have always been class and as such for me this is a must own title.
Online for the last release was ok, but needed a hell of a lot of refinement! Hopefully in this game you will be able to enter into entire racing championships online (clubman/sunday cup anyone?) with prize money that carries over into your main game. If they can implement that kind of synergy between online play and your career mode I would be chuffed.
I would love to see a full list of real tracks that are going to be in the game, Laguna Seca (corkscrew

) and Nurberg ring are pretty much dead certs. I would love to see Donnington (which is a class circuit btw, lets just hope it doesnt get butchered too much to make it more F1 friendly

) and maybe silverstone in there. I would also love to see a return of the GT1 classic deep forest.