They've played twice since then if I remember right and Federer has won both matches.
Federer was up 2 sets to 1 in that final playing one of the worst semi final matches of his career while Novak was playing great tennis. Federer was struggling big time with his first serve too and he just was not in rhythm. If Federer can take 2 sets playing that kind of tennis and Novak playing great then I know for sure Jokers win was a rare one for him.
Federer is not done yet you will see