This article, Throwback Shadow Boxing At Its Best, however is probably the best I have read regarding the current status of the fight.
One thing is for sure: Mayweather is the bigger man and the bigger draw and the bigger personality. He has more to lose than Pacquiao. Much like his fighting style, he is poking and prodding, careful to stay just out of reach. Mayweather has always been the master technician. This time, the ring is optional.
It wasn't too long ago that fighters cared about their place in history. Mayweather love him or hate him, it seems he is well aware of what his legacy is and what it may be. He also, growing up in a fighter's family, remembers better than any of his opponents the spectacle of pre-fights, to him those days are legend and Mayweather likes what his legend is with or without Manny Pacquiao.
I am Frank Chow and I approved this message
Update: The fight won't happen, perhaps this is a maneuver for a better fight date? Or Mayweather really did get to Pacquiao to the point of no return. Disappointing, but I feel this isn't over. I would have appreciated Bob Arum not pontificating though...he never quits.