Re: 2003-2005 Kim vs. 2009 Kim
Definitely being aggressive, really early in the rally. Her backhand CC has been a formidable shot this USO. She's been swiping everyone off the court with the width and heaviness of that shot.
Her aggressive nature was so much that she made Venus have to hit HUGE, just so she could contest equally. Venus really hits huge nowadays, but against Clijsters she had no choice.
Her forehand technique is still dubious though, but her serving has become a primary weapon, rather than secondary.