While I like the idea of the 4.3L going into a future Camaro I'm not sure they would. One of the things they stated during the launch of the new Silverado was that the reason they made the new 4.3L V6 was because they didn't want to be like their competitors and put an engine designed for cars into a truck. So I'm not sure they would flip it the other way. Of course if it could be adapted to better suit a performance application (which I'm sure it could because it shares most of it's parts with the V8's which will share basic design with the LT1) then it might be another way of extending the life of a powerful, fuel efficient V6 in an industry that is switching to FI 4cyl's.
It all goes along with "What is a Camaro?". A question Scott and the Camaro team pull their hair out on a daily basis trying to interpret. Times are changing and while GM has probably extended the life of the V8 for at least another generation yet younger buyers are more willing to explore alternatives that older buyers wouldn't even consider. I would expect to see an engine option from each 4, 6, and 8 cyl's. Depending on what sells best will determine what lives on year to year.