The girl has definitely got talent. From 200-ish to #9 in the world within 2 years is a great achievement.
Once she works up her 1st serve speed to 110+ she will get more freebie points from the top players and possibly challenge for some big titles.
But from what I read about her she is not eager to work on her strength. It worked for Justine Henin pretty well- hopefully after a few blown chances due solely to her serving she will change her mind and actually goes for some muscle mass training.
She gets overpowered by the likes of WS, Ivanovic and Sharapova. But, once the ball is in an extended rally she comes out ahead more often than not.
I think that when the WS retire she will still be in her prime and hopefully will get a couple of majors.