The OP's questions made me feel like a five year old, writing up my Christmas wish list. I am an optimist, and think all the following are realistic. However, like every Christmas morning, we will get some things not thought of, and not get some presents we thought would be under the tree. Christmas morning is just 29 days away.
"LT4" 6.2L, supercharged motor, developing 640 HP, 608 TQ;
$95K base; $120K with all options;
Retain 7-speed manual trans, but also offer optional 8-speed auto trans;
Removable roof like all StingRay coupes (due stiffer chassis).
Wider tires (285/335’s); though maintaining 19"/20" wheel sizes
Twenty (20) spoke "Twin Y" wheels;
Wider/flared fenders, including standard CF fronts;
More aggressive front fascia with larger intake grill;
Larger hood “air exhaust vent”; raised area over supercharger.
Side rocker extensions;
Rear-fender brake intake ducts (like C5 Z06);
Top-rear-fender intake scoops*;
Twin trapezoidal exhaust tips*;
‘Race car’ rear diffuser*;
Larger rear deck spoiler;
Different interior “coloring,” e.g. two-color seats;
“D” shaped steering wheel*.
"Z06" upper-seat embroidered "design"
Exposed CF “halo bar” (to match removable CF roof);
CF "shifter surround plate";
"Z07 Package" with Michelin Pilot Sport Cup tires; different lightweight wheels, carbon-ceramic brakes, std. Competition seat;
Hope for, yet not expecting: CF driveshaft, titanium exhaust, magnesium front suspension cradle.
* Similar or identical to SEMA Grand Turismo car (as per following link)