Before this season most Celtic fans were not high on Williams and would have not have been displeased to see him traded. But he lost weight and turned himself into a /good/ 3-point shooter, which of course is a big part of the NBA game. He's become a key asset for the Celtics, who were the best team in the league in the second half of season and could be in the NBA final.
Poor Josh Richardson--he was playing well for the Celtics, and then they trade him right as the Celtics were starting their second-half run. Now he's with a young and rebuilding San Antonio roster. He played well for the Spurs--but could very well get traded yet again.....