The major change appears to be in the lower grilles on each side of the front bumper. They look very similar to those on the A7 with the more aggressive exterior package. The grilles feature more black mesh, have dark fog lights to blend in, and have a sharp downward angle at the top for a meaner look.
The rest of the car appears unchanged, at least on the outside. The inside is likely unchanged, too. Also considering how minor the changes are, we will likely see the official reveal by the end of 2018, with dealer deliveries happening soon after.