This is a huge fight, no doubt about it, but how it is viewed in history will depend on the outcome and what happens over the next few years. Mayweather-DLH was huge too (and that wasn't 18 years ago), but today it is often overlooked because DLH didn't go on to do much since. Pacquiao-DLH was a big fight, but the way Pacman beat the old legend up and how Oscar ended his career retiring in the corner took some of the shine out of a potential fight for the history books. Moving on to another division, Lennox-Tyson was massive at the time but today we know that it was only a shadow of Tyson in the ring (like DLH above). If Floyd wins this fight on points, it will be quickly forgotten and with time it won't be regarded much higher than his wins over Mosley and DLH. This will be even more true if Pacquaio never fights again or has one or two low profile fights with losses or uneventful wins. A Pacquaio win on the other hand would be a lot more memorable because he would finally take the 0 that has eluded so many. If he can pull off a stoppage, then it would be the ultimate outcome to cement this fight in the history books. What I'm trying to say is that the megafight only feels historical today, but in due time how it is viewed depends on the outcome. This is of course a little unfair for Mayweather, who would need a KO for people to still talk about this fight 10 years later, but that's just how it is.
