On topic Djokovic has got so many points in rankings in last months that his ranking is much better protected than the rankings of the ones behind him imo. I think that Djokovic will be a very solid number 1 for most of next year but behind him, many things may happen from Fed, Murray, Nadal to Ferrer for number 2 to 4 seeds (and Del Po and Berdych can also trouble them).
That's why yes, I see him as number 1 until late last year and overtaking Nadal for the number of weeks as number 1. And will probably stay ahead of Nadal for that stat in the future as well imo.
For the number of slams, I also think there's a good chance he overtakes Nadal for the number of slams.
Actually I expect him to dominate for several years and I fully understand that he aims at Sampras's record of 6 end-of-year number 1 rankings.
Yes, I think that with time going, Djokovic will be more and more recognized as one of the greatest players. Actually, since 2008, I've anticipated he would reach Lendl's, McEnroe's and Connors's category actually (I put Murray with Becker, Edberg and Wilander). So far I put Nadal still a bit higher but it can change.
Really? He needs 4 more. Will he be YE no.1 in 2013, 2014, 2015, 2016? I doubt it. He will be 26 next year i.e. end of 2016 he'd have to be 30 and the no.1 player. His game isn't like Federer with lots of cheap points - he declined a bit in 2012 vs 2011 and no reason to think he'll be better at age 28 than he is now. Don't think that figure is reachable nor do I see him being this committed for 4 more years.
As for reaching Nadal's number of slams, for one that assumes Nadal will stay at 11. Nadal, body permitting, seems to be planning on playing at least the next 3-4 years. If we assume at least 2 of those he will be elite that's 8+ slams he could contend at - chances that he won't win even one of the next 3 FOs? Low. If Nadal ends up with 13 hypothetically, Novak will need 9 more slams to overtake him! 9! That's as many as Lendl in a career!
Even now he needs to win 7 to overtake Nadal! This is with Murray clearly showing that he can hang with Novak on HCs i.e. AO and USO will not be gimmes. Add in Del Potro and some new guys - a Janowicz or someone we've never heard of. The fact is winning slams isn't easy. Novak has the pedigree and talent to win a lot but he'll need some luck too.
Overall I see him ending up in a Lendl like position - LOT of consistency, lot of finals, long time at no.1, but fewer slams than his top rivals (Fedal) and a rung below them in the all-time great stakes. Nadal, like Borg, will have historically a short time as no.1 relative to his stature but in the context of him being no.2 to Federer for so long that's understandable.