Finally a real release date. They also released an official car list for the game. The 2010 Camaro is on the list with a premium model!
http://www.gran-turismo.com/local/jp...arlist_en.html
Difference between Standard and Premium models: Standard vehicles will feature a basic damage model with dirt, scratches and dents appearing on the car in the event of an accident as well as internal, mechanical damage. The more detailed "premium" vehicles will feature the full damage model with more accurate damage such as panels being ripped off. Premium models also have cockpit views available.
EDIT: I was so excited, I spelt Turismo wrong. :(