I would prefer to see Nadal v Soderling. Grudge match after last year and after Soderling mocked Nadal in 2007. In addition, Soderling has a better chance against Nadal than Federer does. It would be a much more interesting match than Nadal v Federer, where (let's be realistic here) the result is almost a foregone conclusion.
Having said that, I always cheer for Roger and I'm still holding out hope that a miracle will happen and he will beat Nadal in the final.