Pacquiao right now would win because he has made leaps and bounds as a fighter. But if we are talking about Pacquiao from featherweight that was mostly jab jab left hand jab jab left hand and was countered at will by someone like a Juan Manuel Marquez. Pacquiao's style at featherweight is all wrong for a counter puncher, especially a counter puncher with a lot of one shot power. Looking at ICB's avatar of whitaker, the second knockdown where the guy came wailing in only to be countered by whitaker's left hand laying him out, is pretty much the way I see the fight going. Pacquiao would be over aggressive and left hand happy and would be countered and probably knocked out. Slick boxing coutner puncher with one punch KO power is a bad style matchup for Pacquiao at featherweight.