A second reason they probably won't ever do it(for the foreseable future at least) is that they wanted to make it more readily noticeable the differences between the V6 and the GT models. And one of the quickest and easiest ways of telling that is with the dual exhausts. But like CJ said give it a few months and there will be aftermarket exhausts available. Or you could always have somebody fab you up a custom setup(but it'll be expensive as hell).