GM's quoted performance for a 1998 LS1 Camaro was 13.9 in the quarter. What does that tell you? Performance estimates from the manufacturer are always conservative.
Just wait until the cars hit the street, and if 13.3 is the best they can do then I'll eat my hat. Stock fourth-gens can hit 13.3 and the 2010 will have a noticably better power to weight ratio.