All I know about price, Mike, is they have alluded to being similar inprice to equivalent optioned sedan, which with V8 starts at just over $31k. If tehy offer teh V6 expect it to be around $27k-28k.
Your Sonoma, like my Colorado did not come in a V8 until 2009. Pricing of a new V8 Colo with similar creature comforts that I would get in a G8 ST, including V8, power and convenience pushes the little truck's msrp dangerously close to $30,000 (29,315) And the G8 is not meant to replace many small trucks in GM's stable. Think of it more as practical SSR.