I don't think this fight hurts boxing as I feel boxing did that for itself with $50-60 pay-per-views that had crap under cards. I feel like that's really where MMA has shown it's strengths over the past 20 years or so now. The under cards have gotten stronger and stronger, there are constantly young up and coming hungry fighters who put on better fights then the main card on many occasions.
In terms of McGregor vs. Mayweather I think it be sweet if McGregor was able to land a left bomb that shocked the world, but I just don't see it happening. Mayweather is too smart and too elusive of a boxer to allow himself to get into some in the trenches battle with McGregor. I'm pretty sure it will just be 3-4 rounds of Mayweather picking him apart and then choosing the time to finish the fight somewhere in the middle rounds as some others have suggested. I wish when they did this, that Mayweather would've had to do a second fight vs McGregor that would be an MMA fight so he could get a taste of the flip side. But alas this is all for the money as most things in today's media realm seem to be about. Either way this will probably be the most tuned into sporting pay-per-view event to date, if I had to guess. At the end of the day though I feel like this is going to be so over-hyped that the fight itself really can't live up to it all unless we get a puncher's chance KO by Connor.