I think Nole is going to want to snatch one win over Rafa during the clay season. Probably not Monte Carlo, maybe not Rome, surely Madrid is his best chance. If Nadal is 2-1 vs. Nole on clay this season going into RG, it will be good for Djokovic's confidence knowing he got Rafa once heading into the big one.
Of course, at this point, it is so far away, you never know what knees are going to do, who's grandparents might die, whose parents might get divorced, or if Federer can wag his finger and ruin the whole thing.
Will Madrid be played on blue clay this year??