CAUTION: Much speculation and educated guesswork in this thread.
It's become apparent that GM is moving forward with a TT 3.0L V6 for various products. Cadillac XTS, Buick LaCrosse and Enclave, next gen Impala, ATS and next gen CTS have all been rumored to get it. As opposed to an all out performance engine, the TTV6 looks like it'll be intended as a very fuel efficient, midlevel performance prime mover, for GM luxury car buyers. Just my guess, but I'd peg it's power in the 375-ish range.
At the same time, GenV smallblock development will continue for those products which are deemed to require a V8 - trucks, Corvette, certain versions of the Camaro, ATS and CTS, etc.
Anyhoo, there is a good possibility that Camaro may end up with both of these motors, especially if Mustang delivers both TTV6 and V8 on it's next gen car. Let's say a 375 hp TT 3.0L V6 as a midlevel powerplant and a 450 hp GenV smallbock as the halo car.
You can bet that for the halo car (oh, what the heck, let's call that a Z/28 ) you'll pay more than you will for the the midlevel car, eventhough a GenV smallblock will cost way less to manufacture than a twin turbo, intercooled, DOHC V6. It will be a CAFE strategy to funnel people into the higher MPG variants.
Who here would pay more for a cheaper to produce V8 vs a TTV6?