So this means either of three things going to happen. The first speculation is that the next generation G8 and Camaro will have the new Alpha platform. Which means they'll be smaller. The second option that GM could continue into the production of the Sigma platform, which debuted back in 2002 in the first-generation Cadillac CTS, and that could make it into the next generation G8 and Camaro, so they stay big. However, with GM's financial situation, there is also chance that GM could start to adopt more FWD designs, because it's cheaper to make.
If you've got any suggestions or speculations, write down in the comments