It is an interesting idea but I do think that he is bitter that he has dropped in the rankings to Andy. I also think that if it was a 2 year ranking system the smaller tournaments would really suffer it would also really only benefit the top players.
"I try not to pay too much attention to the rankings, but to be realistic, playing three Masters Series finals in a row and winning a 250 event (Belgrade) is incredible success " from Djoko sounds like sour grapes to me
It's astoundingly arrogant, as I didn't notice him being particularly vocal on this subject when he was playing like crap for the second half of last year and Andy was racking up the results. He was creeping back up in my estimation from his previous low, but he's gone back down again.
I was reading a thread on this on BBC 606 earlier and it turns out that he and Nadal have been talking about this and seem to be launching a joint offensive. Nadal is coming at it from the angle of 'it would help prolong careers as you wouldn't need such a packed schedule to defend the previous year's points'. Both of them are a bit out of line in this regard.