I came across an article in the March 2008 Motor Trend Magazine that says that the V-8 will be the first car produced, to be followed by the V-6. I'm sure not all the info is correct, but here is how it reads:
2009 Chevrolet Camaro
Chevy's nostalgic pony musclecar will leave the starting line well after it's rival Dodge - Camaro coupe production starts in February 2009, with a ragtop likely to follow in December. But maybe they're runnung a bracket race, with each car achieving similar sales at the finish line. Chevy envisions 65,000-70,000 initial sales, blooming to 100,000 when a V-6 comes online; Dodge totals are expected to be half that. Like the Challenger, the Camaro gets a proper B-pillar for crash-worthiness and a toned-down interior. Engine choices are likely to be cribbed from it's Pontiac G8 platformmate, including a 6.0-liter LS2 V-8 (perhaps juiced to 400 horses) with a range-topping 500-horse V-8 rumored to follow. The base engine should be a 3.6-liter V-6, but don't expect it to mimic 1969's rock-bottom pricing.
As Always, Camaro will likely outperform and undersell archrival Mustang.