Word from AutoExpress is that Toyota is going to pull out the big reveal of the 3rd generation Prius in January of 2009 at the Detroit Auto Show. Toyota chose the New York Auto Show to reveal the 2nd generation Prius back in April of 2003.

There was a period of about 6 months in between the NY Auto Show and when the car was actually available for purchase in the US. Not sure if that means that the Next-Gen Prius will be available in July 2009 or not, but that's a pretty good educated guess at this point. Perhaps a 2009.5 model year?