Pontiac was GM's 3rd best selling company last year behind GMC and Chevy. Cadillac was 5th.
Pontiac INVENTED the muscle car with the debut of the GTO back in '64. And REDIFINED it when they released the Trans AM Super Duty. It makes no sense to drop it.
GM was talking about turning it into a niche and it's fate still unannounced.
Have a look at this.
Grand Prix Net: Goodbye Pontiac