I think Nadal has to be the favorite considering he has shown he is the greatest player in the history of the game on clay, and has dominated Federer. However, if anyone can beat him it is Federer, but Federer has to modify his game for the surface and hasn't shown a willingness to do so. I give Fed a 40-60 chance and Nadal a 70-30 chance of winning. Nadal may decide to take an extended rest an go out early in this before he gets to Federer so that he will be fresh for the French, but I don't think his ego will let that happen. A win for Rafa over my favorite player (Federer) in 3 sets.