Djokovic will win this easily. Del Potro hasn't defeated a top player this year, he lost in straights against very average Nadal, additionally he's still struggling with physical issues, so I even doubt Del Potro will be able to finish this match, considering it's intensity.
So Soderling isn't a top player anymore?
For me Del Po is a better clay mover than Djokovic and he has the power to hit through Djokovic's amazing defence. Physically Del Po said he was fine so it's going to be an absolute cracker. I think the streak will end friday.