So you are referencing forum that references an article from April of 2010? Not the most current of sources. Anything is possible. My guess is they will be very close in weight. The ATS proves what GM can do and the Camaro haters (and lovers) have made it clear weight is at the top of the list for wants.
Mods: BBK Intake, BBK LT's and High Flow Cats, Corsa Cat-back exhaust, Hurst short throw shifter, SLP skip-shift eliminator.
7/1/09 Placed order for IOM/IO int/ SS/RS 6M
9/26/09 Took delivery!