Image source, Getty Images

Are they past their best? Should the fight have happened sooner? How much will they earn? All big questions.

But the biggest of all is, of course, who will win?

The bookies make Floyd Mayweather favourite, but the gap is closing, with reports of a rush of money against Money...., external

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HBO Sports president Ken Hershman: "This is the Super Bowl of boxing and we're happy to be part of it. They're the two greatest boxers of their generation, they're in the same weight class and how often does that happen? I never realised until I got here today, walked the red carpet and saw all the cameras what a special event this is. This fight will transcend boxing. Tune in on 2 May - it's going to be very special."

Image source, Twitter

Alex South, external on Twitter for the BBC: "Pacquiao said it's his biggest fight. Mayweather to the BBC: 'It's just another fight.'"

Strange to think that, as it stands, Mayweather and Pacquiao have only ever met once, at a basketball game in Miami a couple of months ago. But in a few minutes it will time for the men to come nose to nose for the traditional face-off - and only then will the fight seem like a reality for the first time.

Righto, stand by for the news conference proper, which is due to start now. But isn't going to. I'll keep you posted...

Image source, Getty Images

Should this fight have happened sooner? Have your say using #bbcboxing.

Kevin Chadwick: , external"The Manny that marmalised Hatton, smashed Cotto and rearranged Margarito's face is the one who should have faced Floyd way back."

Nathan Bertram:, external "Mayweather to win. He could have had this fight years ago and knows Manny is different after the losses he's had. Come on Manny!"

Andrew Priestley:, external "It'll be great to finally see Mayweather and Pacquiao go toe-to-toe in the ring. It's just a shame it didn't happen 5 years ago."

Floyd has been grabbed by BBC World Service's Ade Adedoyin, and here are a few quotes. "To be involved in the biggest boxing fight in history is a blessing, but I've already been in the biggest fight in boxing twice before. I'm going to be smart, be first and listen to my dad [Floyd Sr] - and I'm sure my dad is going to be right..." Pacquiao's trainer, Freddie Roach, reckons Floyd Jr should have uncle Roger in his corner instead..., external

Dan Rafael, ESPN boxing writer: , external"Press credentials issued for #MayweatherPacquiao presser in LA: 700."

Have your say on the mega match-up between these two boxing giants on 2 May.

Who do you think wins? Can Manny Pacquiao end Mayweather's streak or will the 'Money Man' leave the MGM Grand victorious for win number 48?

Get involved using #bbcboxing on Twitter, external or go to our Facebook, external page to post your thoughts.

Image source, BBC Sport

Alex South, BBC World Service: "Half of Mayweather's bodyguard team. They dwarf the man they look after. Some would ask why he needs so many."

Image source, Getty Images

Mayweather has arrived on the red carpet, somewhat behind schedule. As such, I'm not confident the news conference will start on time. They're supposed to be on the dais at 2030 GMT...

Image source, Getty Images

BBC World Service just grabbed Michael Buffer for a chat on the red carpet. Buffer is the man with the trademark that helps define modern boxing - "Leeeets Get Readeeee To Rumbleeee." There was a feature about him on the BBC Sport website not too long ago, which you can read by clicking here.

"I wanted a handle, a hook, just like at the big car races: 'Gentlemen, start your engines!' I wanted something that would bring that energy back, because the fighters were the stars of the show and I wanted to introduce them with the energy they deserved.

"I tried a few versions and nothing seemed right. But then I thought about the great Muhammad Ali - in interviews I had heard him say 'I'm ready to rumble'. I fine-tuned that to what you hear today."

Manny Pacquiao, external got a few early blows in before the press conference: "I'm here to prove that I can easily beat the undefeated.

"Beating Floyd is good for boxing. When athletes have great success, their success goes to their head. That is bad for boxing.

"The Lord my God that I am serving will deliver him into my hands."

Floyd Mayweather confirmed the fight on 21 February by posting a picture of the signed agreement between the two fighters on a social media account.

He wrote on his webpage: "What the world has been waiting for has arrived. Mayweather vs Pacquiao on May 2, 2015 is a done deal.

"This will be the biggest event in the history of the sport. Boxing fans and sports fans around the world will witness greatness on May 2."

Image source, Floyd Mayweather

American network Showtime Sports, external asked Floyd Mayweather if he would like his post-fight meal to be cooked up by celebrity chef Gordon Ramsay.

To which Mayweather replied: "No disrespect, I don't even know who that is."

American Floyd Mayweather Jr is undefeated in 47 professional fights, a run stretching back to 1996.

He defeated Argentine Marcos Maidana on points in his last two contests, extending his career earnings to more than $400m.

Philippine Manny Pacquiao has won 57, lost five and drawn two of his 64 professional fights.

The six-weight world champion recently defended his WBO welterweight title after beating Chris Algieri on points in November last year.

Image source, ALAMY

Manny Pacquiao's manager Bob Arum: "Manny has a better arsenal. Floyd is a great defensive fighter but this guy, when he is focused, has all the tools to drive Mayweather crazy. He punches from funny angles. Ask Ricky Hatton about him [Pacquiao knocked the Manchester fighter out in two rounds in 2009]."

Is this the biggest fight in boxing history?: "I go back to the Ali-Frazier fight, we had no satellites then, no social media, it's hard to compare. I know my country stopped. The fight was on a Wednesday and nobody went to work. In this era this is the biggest fight and that's the best you can say. People finally got sense and put it together."

Image source, AP

Manny Pacquiao's trainer Freddie Roach: "When I heard the fight was on, I was the happiest guy in the world. We have had two training days and I am happy with where everything is. By the time the fight comes round Manny will have everything glued in his head.

"My guy is too fast, he hits too hard. I think Floyd's legs are shot. He says he wants to stand and trade more and entertain the fans more, but I don't think that is true. He has to say that. I [trained] Oscar de la Hoya and had him beating Floyd in the first six rounds of their fight in 2007. I know how Oscar won those rounds and I know how he lost the fight as well.

"I have been in some big fights before, but this is something else. It makes everything else we have been involved with like a little game show."

Manny Pacquiao and his connections have already strode the red carpet at the Nokia Theater, Mayweather is expected to begin the rounds of the world's media in approximately 25 minutes. Freddie Roach, Pacquiao's trainer for the last 15 years, stopped for a chat with BBC World Service...

... in truth, hardly any tickets for the 18,000 capacity MGM Grand Garden Arena will be on sale to the general public, but they are already being advertised on the secondary market for $25,000 - and that's just for a spot on the floor. If you want to be ringside, Pacquiao's promoter Bob Arum says you'll need a $250,000 credit line with the MGM Grand Casino. And this time, celebrities won't be getting freebies - Jack Nicholson, David Beckham, Rihanna and Bobby Davro will be expected to pay upwards of $100,000 for the privilege...