With Nadal’s loss to Andy Murray, Nadal will move from #2 to #3 and may drop to #4.  Novak Djokovic has already reached the quarterfinals which matches his results last year.  At the very least, he’ll keep the 8310 points he has now.  Rafael Nadal is 1000 points ahead of Djokovic, but because he is the defending champ he loses 2000 – 360 = 1640 points and will have 7670 points after the Australian Open, which is less than the 8310 points Novak Djokovic will have after the Australian Open.

If Murray loses in the semifinal, he’ll have 7320 points and still be behind Rafa in his number 4 slot.  Should he reach the final but lose in the final, Murray will have 7800 points and become number 3 in the world.  Should Murray win the Australian Open, he’ll have 8600 points.  This would make Murray number 2 if Djokovic doesn’t win his quarterfinal with Tsonga.  If Djokovic does win his quarterfinal, he’ll have 8670 points at the very least (for reaching the semis) and that will leave him just ahead of Murray.

Djokovic can become number 1 in one scenario.  If Federer loses in the quarterfinals to Davydenko, he’ll lose 840 points and be at 9710 points.  Djokovic, who lost in the quarters last year, will gain 1640 points if he wins the Australian.  That would put him at 9950 points and just ahead of Federer.  If Federer reaches the semi, he’ll have enough points to remain number 1 even if Djokovic wins the title.

In a nutshell, Djokovic becomes number 2 unless he loses in the quarterfinals and Murray wins the Australian Open, in which case he becomes number 3 and Murray goes back to number 2.  If Djokovic wins at least one more round or Murray doesn’t win the Australian, then Djokovic becomes number 2.  Murray becomes number 3 if he reaches the final, and becomes number 2 if he wins the final and Djokovic loses to Tsonga.  And Djokovic becomes number 1 if he wins the Australian and Federer loses to Davydenko.

Given the current form, there’s a strong likelihood that Nadal will be number 4 after the Australian Open.  Djokovic had chances to become number 2 back in 2008 during the clay season, but lost to Nadal.  Djokovic has never been number 2.  And he’s definitely never been number 1.