The wieght distribution may not be 50/50 with the V8, but it'll still be darn close. You're adding 100-150 lbs to the nose when you choose V8 over V6. But 2010 5thgen has a point; I'd expect some different suspention setup, and different tires, etc to accompany the V8.
I think you touched on a point that I've been thinking about though:
You've got a V8 and a V6. Which one was the afterthought, right?

From what we're all gathering with all these little tidbits of info....NIETHER!!! I think they've put equal amounts of effort into both models which ensures a quality, no-compromises vehicle in ALL levels! That excites me more than any of the V6 talk.