I could see Djokovic start owning the French Open if Nadal's health keeps failing him over the next few years. Nole's defensive counterpunching style of play is so conducive to clay court play, it's hard not seeing him roll off a few RGs. Fed's reign of being the 2nd best clay courter in the world seems over, so the door's open.
Unless Rafa gets back to business, AO/FO could become a thing for the Djoker. I realize that this is a crazy-sounding thing to say given that he's yet to win a single Roland-Garros