the a-body hasnt existed for 20 years...theyre not going to reincarnate an ancient platform, as it wouldnt be competitive just based on technology.
i think that youre mistaken on the weight of the camaro. the camaro is closer to 4000 than 3000. the mustang is very light, but the camaro is not. it still weighs less than the challenger, but its no where near 3000-3500lbs.
http://www.examiner.com/x-8811-Detro...-2LT-RS-Review