2013 Shelbys? Big development program or just small scale low budget?

I read someplace that Ford or Shelby has already signed off (approved) the final design for
the 2013 shelby. So my question is--will this still be on the same body shell?
Was it really designed at Shelby American in Las Vegas rather than in Dearborn (they released a picture but I can't tell by the background full of drawings if it was in Dearborn or LV). Do you think there were many variations with changes in fenders, grille shapes, etc. or just one car with very minor detail variations like where to put the snake badge? I drove the 2011 Mustang GT on a racetrack (Fontana) and found it to be satisfying so I think they have a good platform but wonder if emissions laws for 2013 will hurt their development plans.