The very recent past. Do you really think Djoko's improved so much since then? Come on. Even if he has -- so had Bagh's. Big deal.
Federer's still the same guy who cremated all of the "up-and-coming players" in straights at the AO, just now he's going through a rough patch on his worst surface (just may have emerged from it, we'll see).
I don't know who the "next great player is", but I think that anyone who will be in their prime while Federer is still in the prime or even sub-prime (so long as not decline) of his career will have a tough time being great, unless they can make some inroads after Federer retires.
Maybe Djoko is young enough. But I don't see him doing anything while Federer's still here.