Sorry to disappoint, but told ya so.
today from Lutz taken from autoblog.com:
"The G8 will not be a Caprice after all. I'd mentioned it, and said we were studying it, giving it a serious look, because a car like the G8 was just too good to waste.
"That's all still true. But I have to say that, with my new "marketing" hat on, upon further review and careful study, we simply cannot make a business case for such a program. Not in today's market, in this economy, and with fuel regulations what they are and will be."
I've also heard the Z28 is going away. (not verified yet).