Hiring Carols clearly is a good move. I think Justin Henin has the best techniques among women, of all time. Rubbing some of that off is very valuable.
Li Na has power, but needs someone to help tame it. She has a tendency to misfire. At 31, I hope she can have a couple of more good years (and $).
Among new Chinese players with potential, there is a Zheng Saisai, 18, just got into the quarters in doubles. Very good athlete all around. Very alert. In the two last rounds with some 10-20 ranked players, she was the star.