Doesn't make a lot of sense to me. The American promoters are going to have to hype Khan an awful lot to sell this fight, even if Khan can get over the obstacles that are in the way of this fight.
Khan has to beat Marcos Maidana on December 11 and then fight a unification match next spring against the winner between world title holders Devon Alexander and Timothy Bradley, who are due to meet in January.
That's a two tough fights before they can think about a fight between Khan and Mayweather.
Also Khan is a lightweight, fighting at 135 lbs, Mayweather is back at welterweight the 147 lb class, but has fought at 154 Lbs when he fought De Hoya. So any Mayweather/Khan fight will be held at Welterweight (147 lbs), I suspect.
Any unification bout between Khan and the winner of the Alexander/Bradley fight won't take place until next spring at the earliest and they want a Khan/Mayweather fight next fall. That's not a lot of time for Khan to bulk up and get comfortable at 147 lbs.