The camouflage can't hide what this car really is. Just take one look at that rear wing. It's actually slightly different than the current TT RS' wing, with some small end plates presumably improving the car's aero. It looks like both the front and rear bumpers will get updates, though it's difficult to make out any real details through the camouflage.
We don't have any further details on the car, but don't expect too much to change under the skin. The engine, transmission and quattro all-wheel drive system should all carry over, maybe with a small boost in power. Hell, we might even see a stripped-down lightweight package to improve the car's performance.