There certainly is a lot of performance comparison between the Gt500 and the future Z28, which is fine. But everyone will surly realize that there is VALUE in a completely new body style. I like the look of the GT500 but I LOVE the look of the Challenger and the new Camaro (because it's novel). All of these cars are fast, but only two offer the new look as a BoNuS.
Unfortunately the Mustang is predominantly a preserved body style that is nothing new to look at. Drive down the street in a Camaro or Challenger and turn heads but drive a Mustang and you will most likely go unnoticed. In a couple years we will all be desensitized to these body styles, but right now Camaros get noticed. After all, that's why you bought a car like this...isn't it?