I think Nonito Donaire has the most potential. He has his Filipino and American roots. He is overshadowed by the pacman but I do think that if Manny retires, the Filipinos will learn to accept his swag.They are just too accustomed to Pac's good guy nature.
With a lil bit of luck, careful matchmaking, and proper marketing I'd say Khan and Ortiz. Donaire would be a prime candidate if he was a welter.
Khan and Ortiz are the obvious choices. But both have a lot more to do to be classed as top 10 p4p material.
khan/ortiz/alavarez all have the potential, ward and donaire are obvious guys but I dont think they will ever be mainstream.