Defending champion Djokovic was the last of the four men to make it through to the final four, given a thorough workout by Spain's David Ferrer but still a straight sets winner.
It is anyone's guess who will claim the title in this compelling opening slam of the season.
Nadal is set to take a month's sick leave once the final is over, with or without him in it, but showed incredible passion and determination in a testy victory over Thomas Berdych.
Federer, meanwhile, has been grace and poise personified, looking back to his former best and ready claim a 17th grand slam title.
Murray, of course, has yet to win his first, falling in the final in Melbourne in the last two years.
His progress has been less than testing so far and he enters his semi-final against Djokovic in much the better physical shape.