Mosley can't pull the trigger anymore, Khan would win this. There's much more important fights for Amir out there anyway
Personally i think its a great fight for a number of reasons , if he does fight @47 (Khan) he can quite easily go back to 40 or if he gets comfortable have the Jr WW's such as Bradley and Peterson meet him there , and then there's Marquez , one would think due to the longterm GB connection that the fight could be made as Marquez is still theoretically a free agent , but im unsure Marquez would accept that fight based on styles and age
Maybe this is a good fight for Khan right now, since Peterson will likely go on to fight Bradley and the winner getting Pacquiao in the fall, this leaves Khan dry. Might as well move up and face Mosley and see what he can do at 147.
Mosley vs Khan sounds good. Mosley is considered shot at this stage in his career so he has nothing to loose. Khan on the other hand is not so lucky. He's trying to make a good enough name for himself, so he could be relevant to fight Mayweather. Should he fight Mosley, a win is mandatory or he could kiss a fight with Mayweather goodbye.