Some of the answers to this thread are projectile vomit worthy.
I don't know why anyone would go around bashing Novak for anything he's managed to do. (The AO is a lesser major, he hasn't dominated as much, etc) because when you say those things you're essentially saying "I'm a rabid Fed or Nadal fan and will do anything to uphold my chosen favorite's place."
A major is a major. (at least in this era, when the Australian is compulsory.) Beating Federer, both before he got old, and now that he is... and Nadal, both before and after his injuries, is STILL relevant. Djokovic is at the VERY least worthy of the ATG conversation, and if he bags a French, even if he NEVER wins another title after that, he won't be totally out of place in the GOAT discussion. At his current level, it would be silly to say he'd never win another, though.
He's reached the Semi's or better in 19 of the last 20 slams. Until this year, essentially the only obstacle in his way of the French was the single greatest clay court player in the Open Era. He has 5 straight SF or better at Wimbledon, and EIGHT straight at the US Open.
Even IF he's declining, and a player as fit as Novak is unlikely to decline rapidly, 1-2 more majors is almost certain, and 3-4 is a definite possibility.
Worst case: 8 slams, no French, 4 YECs.
Likely: 10 slams, no French, 4+ YECs.
Best Case: 12 slams, French, 5+ YECs.
In what way is ANY of these possibilities not worthy of ATG status? In what way is the best case not worthy of GOAT discussion?
Probably a typo but less chance 
