I agree that they should have been able to get the Cd lower - a slight taper on the sides would go a long way, and flat wheels would be better, as well.
Having said that, it is a short car (front to back), and that makes it harder to get the Cd a whole lot lower; and it is 0.1 lower than the iMiEV. It is better than any other EV except the Model S, and only a little bit shy of the original Insight and the current Prius. If the production car is forced to have optical side mirrors, then the Cd will be worse.
They did lighten the chassis a fair bit, so it weighs ~400 pounds less than the 2013 Leaf even though it has a 4kWh larger battery. We'll see what the real world range is - I think ~120 miles is quite possible, so that is about 36 miles farther than the 2013 Leaf.
Some more real pictures:
