prior to the AO match Djokovic had only won ONE tight match against Federer, in which he won less games in total. All in all he had won 4 sets (3 on TB) in 6 encounters.
Federer finished 2007 strongly with wins in USO, Basel and TMC
Suddenly Djokovic wins 3-0 in a match in which Federer never had a chance, in a tournament in which he almost lost to Tipsarevic lol. After that he loses to Fish lol and Roddick superlol.
It's not beyond reasonable to think that Djokovic could have won the U.S. Open in straights (having had set points in both the 1st and the 2nd). The match was decided by a couple of points. So Djokovic came back strong(er) at the Australian Open. It's not like he came out of no where; there was nothing "sudden" about Novak's rise.
As for Tipsarevic: he was playing well in that match (52 winners to 47 UEs). And Fed wasn't playing badly, either: 96 winners to 64 UEs. Unless we're going to attribute every five-setter Fed plays against a lesser player to having mono...which would mean that he has had mono his entire career.
As for Fish and Roddick: Fish usually kept it kind close and isn't routinely blown out, so him running off with a win is not surprising. It's undeniable that he has the type of game that can win against Federer. And Roddick has beaten Federer before 2008, so you can't exactly say mono is what determined the match. Besides, Federer has had worse losses in Masters (Canas and Hrbty come to mind), whereas both Fish and Roddick to their credit have finished inside the top 10. Did he have mono in those losses, too?
Fed may or may not have had mono, but if he did, it was not what led to his losses that year. Unless, of course, we're saying that he goes undefeated in 2008 without mono.....