After doing a little more research, it now appears as though G.M. has done away with the "Base" model, and the new base is at least equal too, or better than the C6 Grand Sport, but it is no longer called a Grand Sport.
If that is true, then the price increase is only $3,000 which is acceptable, given the many improvements. However, this all remains to be seen. Since I'd never purchase a totally new car in it's first year of production anyway, I'll decide in the spring of 2015 if I gotta have one or not.