According to Le and Scott Coker of Strikeforce - Le will return in the early part of 2010. He is not officially retired - but he is no longer dedicated to mixed martial arts.
I've gathered this info from several articles and interviews. Here is one interview in particular where Le mentions his possible future. http://www.octagonbuzz.com/exclusive-cung-le-interview/ CL: Scott [Coker] and I have had discussions about this already, and we’ve talked about maybe a warm-up fight after such a long layoff, maybe one on CBS by the end of this year.