Does anyone realize how many points Djokovic has to defend this year. He started performing well at IW last year and made the final. This year he bettered and won it. But from this point on he has more to defend than to gain( other than clay Master's series). He has two Master's series titles to defend, two GS semifinals, one GS final, one master's series semifinal and Vienna if I remember correctly. So we have to wait and see.
this is kind of a weird thread
anyway, you forget that roger also has a lot of points to defend doesnt he? besides djokovic may win a few points during the clay season.
It may not happen this year, but there's a possibility.