Federer, the 16-time Grand Slam winner, was knocked out of the Australian Open 7-6 (3), 7-5, 6-4 on Thursday by 2008 champion Novak Djokovic.
Before the tournament Nadal was going for his fourth straight Grand Slam win and Federer was aiming for his fifth Australian title.
"I'm looking forward to watching that match tomorrow from my bed with some popcorn," Djokovic said. "David played a fantastic match against Rafa even though Rafa was struggling obviously with injuries.
"They are in top shape. Andy has been in top shape on this court. It's a Grand Slam final, anything can happen. I believe in myself."
It will be the first time since 2003 that Federer will not hold any of the four major titles, and the first time that neither Nadal nor Federer will not feature in a Grand Slam final since the Australian Open in 2008, when Djokovic beat Jo-Wilfried Tsonga.
The scenario could open the door for Murray to become the first British Grand Slam singles champion since Fred Perry in 1936 when the final is played Sunday night at Rod Laver Arena.
It is the second straight Grand Slam in which Djokovic has knocked Federer out in the semis. At last year's U.S. Open, the Serbian player saved match points before beating Federer in five sets to advance to the final against Nadal.
"It's really one of the best matches I've played in a while," Djokovic said.
The last time Federer was beaten in straight sets in a Grand Slam tournament was here in 2008 -- against Djokovic.
Federer won 11 of 14 points to come back from a service break down to take the lead in the second set after the two traded tit-for-tat booming forehands and chip backhands during the opening set. But Djokovic broke back later in the second set and took his power strokes into the third set to win in an even three hours.
It was the 20th meeting of the pair. Federer still holds a 13-7 edge.
"It's not the end in any way," he said. "Sure, it's disappointing and it hurts in the moment itself. I wish I could have won here again for the fifth time.
"But that's sometimes how it goes. Doesn't mean the guy that doesn't win the tournament can't play tennis. That's sometimes how things are portrayed. I had a great season last year, and I think I'll have another one this year."