Will Murray prevail?
Roger Federer took almost as much time (1 hour 15 minutes) to complete his press and media commitments as he took to win his semi-final (1 hour 28 minutes) encounter with Jo-Wilfried Tsonga on Friday night.
As he happily moved from camera to camera, language to language, even asking me about my kids before we hit record on our BBC Sport interview, Federer looked cool and calm and not remotely perturbed by the prospect of facing Andy Murray for the title.
This will be his 22nd Grand Slam final, a chance for a 16th major title, and over five sets Federer is the king. Why should he be concerned?
Andy Murray poses for photos with fans after training on Friday
Murray has beaten him six times, including four in a row between October 2008 and March 2009, but, as Federer enjoys pointing out, those were all best-of-three-set matches.
It was pretty clear, when we chatted behind the scenes here at Melbourne Park on Friday night, that the world number one relishes the longer contest. Anyone, anytime, any place.
"It's much more intriguing for me because it really shows how good you are mentally, physically and where your game is at," he said.
"Best-of-three-set play can sometimes go by in a flash. Here we will have much more time to solve the problems we have so I'm excited about playing him in another Grand Slam final."
Excited? Come on, Rog, what you really mean is: "I'm ready to give him the same sort of stuffing he got in New York."
Which of course may happen.
Federer starts the strong favourite (forget all this "50-50" nonsense) and almost certainly wins, possibly heavily, if he plays as well as he can. But I'm convinced it will be closer this time.
For all the coolness and magnificently-played mind games, Federer clearly gets irritated by Murray, who holds a 6-4 advantage in head-to-head contests.
The Swiss feels the need to place an asterisk against several of the losses, reminding us, not without justification in some cases, about injuries and illnesses.
On other occasions, such as the 2008 Masters Cup in Shanghai, he has simply been outplayed by an inspired British number one.
And remember, the last time Federer played a five-set final? Juan Martin del Potro twice came from behind to beat him and claim the US Open.
For all the great man's dominance of the modern game and for all his love of the five-set duel, Federer has lost three recent major finals - Wimbledon 2008, Australian 2009, US Open 2009 - in deciding sets.
If it goes long, Murray simply has to keep believing.
At least he'll be refreshed after two full days off. At the 2008 US Open, he played his rain-affected semi-final with Rafael Nadal over the Saturday and the Sunday before coming back on Monday to play Federer. He was annoyed and disappointed he couldn't give his best in the final.
He thoroughly deserves his place in the final, dropping just a single set on the way, and brave decision-making - as well as audacious shot-making - has got him this far.
The first hour of his semi-final with Marin Cilic was spookily similar to the one they played at the US Open. Murray was reserved, on the back foot and dropping balls short. It was asking for trouble.
The Scot has refused to change tactics against big hitters in the past, perhaps hampered by a stubborn belief in his own way of doing things, but here he needed to look at himself, look at the game, look at the scoreboard and take a reality check.
He shifted to Plan B, playing flatter across the net and deeper to the baseline, and when he produced that extraordinary passing shot, chasing back the lob, the match swung. Bingo.
It wasn't as devastating a performance as the Nadal win but it was still 10 out of 10. Turning a match like that on its head, under pressure, was an immense achievement.
His reward? A second Grand Slam singles final, the first British man to experience that since Bunny Austin in 1938.
The tournament had started with a lot of questions about Murray's serve and I confess to asking one which provoked a frustrated snigger. Another guy asked a plain stupid one and he got much worse. Murray can't stand being asked questions about his serve.
"Nobody ever asks me about my return!" he said to my colleague, Vassos Alexander, last week.
"How's your return?" Vassos fired back.
But the serve warrants discussion and praise because, with the obvious exception of round one under the Rod Laver Arena roof, it has been a roaring success.
The second set against Cilic, which he surely had to win, featured a first serve percentage of 77 - a tremendous number for a guy who sometimes slips below 40.
And the second serve - much derided over the years and seen as the obvious weakness in Murray's make-up - has been bigger and deeper, sharp and decisive. In short, a total revelation.
His average second serve speed, over six matches, is 91mph. Against Nadal, it was 95mph. These are figures which have definitely improved in the off-season, and now, with a decent body serve to call upon, the shot is actually winning points.
For example, set point down to John Isner in the fourth round, he fired a big second serve into the body. The return came back, but Murray was on his way to finishing the point and snaffling the American's one big chance in the match. There was a similar delivery, I seem to remember, on a crucial deuce point in the final game of the first set versus Nadal. Brave stuff indeed.
The statistical analysis could continue forever (13 out of 16 serve-and-volley points won versus Nadal, only eight unforced errors in the whole match versus Isner), with most of it reflecting favourably on Murray.
But now the scorecards can be ripped up, the figures erased from the hard drive, because it's all in the mind.
It's about one guy stepping out against another, under the glare of a watching world, and bringing out his best.
"I believe I can do it," says Murray, with a smile and real purpose. "I'll give it my best shot and I'm three sets away."
A huge UK television and radio audience will tune into tennis on a cold January morning to see a potentially momentous happening: Federer v Murray for the Australian Open title.
Who will prevail?