Roger Federer has reached the Australian Open semifinal every year from 2004-2016 except for 2015.  I expect another semifinal appearance for Federer is close at hand.

ROD LAVER ARENA

[4] Stan Wawrinka (SUI) vs [12] Jo-Wilfried Tsonga (FRA) – Stan should win this match, but these two players each impose their will on an opponent through blunt force.  Stan has been the best practitioner of this form of tennis for a few years, but Tsonga is adept at it as well.  If Stan is error prone or Tsonga is on, this result can certainly reverse itself.  

[17] Roger Federer (SUI) vs Mischa Zverev (GER) – Roger may drop a set here, but he should be able to chip enough returns into play to win this match and reach yet another Aussie semifinal.