I have a feeling that the US GTI might only end up with XDS. Since that nice 'torque vectoring system' was developed for 'small-winding english roads', they'll probably nix it for the sake of lowering the cost of the GTI in the North American market. Or, make it an optional feature.
I had the same thought when I first heard about the two different models being offered. I think it is a trategy for VW to stay competitive performance wise and yet keep the cost down for the base model which is fine for most consumers. That means that the performance model will be priced to be low volume (read expensive) and therefore very likely not fit for the NA market. It would probably hurt R sales too much so something has to give.