I think at this point, after over 2 years of bickering, it's safe to say this will never happen.
Pac answers to Bob. And that's just the way it is. Should it be? No. But is it that way? Sadly, yes.
The only way this fight will ever happen is if Mayweather and Bob Arum agree to terms. Not Manny Pacquaio.
Disagree, as pointed out earlier this week, Pacquiao showed he was his own boss by refusing to fight Hatton unless Arum took money out of his own pocket to make it happen. Pacquiao is Arums boss, not the other way round, and he can fight pretty much whoever he wants if he insists.