It's all going towards the super classico of tennis and it will be extra interesting this time.
It would be crazy to see Fed and Nadal complete their own career-slam of Finals against each other. This surface has always been Fed's and the one place that Rafa couldn't touch him. I still have trouble believing Rafa could beat him here, but the potential of such a match would be bananas.
TBH I'm on the fence about them meeting in the finals. I think Rafa should get by Nando but Youzhny/Wawrinka could be tough. If Rafa makes the final I'm not sure I want Fed there. His problems with Rafa go way beyond surface. If Rafa beats him convincingly here then what? Rafa is just so relentless, it seems inevitable he'll win the USO one day. I just don't want it to be against Fed.
I'm almost the exact opposite (and I think we could easily context that you tend to pull for Fed while I tend to pull for Rafa). I don't particularly want Fed to win this year's Open, and would be fine with Nole taking him out. The only reason I'd want him in the Finals is because of the potential of seeing them finally go heads up at the USO.
The Fed's surface of choice vs Rafa's seeming advantage H2H against Fed would be extremely interesting. And it has potential GOAT implications as well, because with the career slam and the record number of titles it's hard for us Sampras fans to argue against Fed. But if, somehow, Rafa were to complete his career Slam against FED, on his final surface of refuge, and run his career record against him even more lopsided...it becomes harder to argue Fed as the GOAT if he can't beat the best of his own time.
Either way, it'd be by-far the most interesting combo no matter what the outcome.