Well I think what it comes down to is that The General really doesn't give a damn about the UAW anymore. They have gotten rid of the majority of their UAW staff with the recent cutbacks, and thereby, have no one really to get worried over the whole thing. That said, the big question lately has been what exactly GM plans to do with the car after the Oshwa plant up in Canadia (thats right, I called it Canadia!) running. That plant will be building the Chevrolet versions of the Zeta platform, and presumably the LaCrosse replacement as well, however plans for the Pontiac have yet to be made.
...Which is strange, as the plant that will be building the Commodore/G8 will not only be sending cars to America and Australia, but as I understand it, the cars will also be sold in Europe as well both on the mainland and in the UK. There has to be an eventual limit by which the capacity is maxed-out, and although VIPER noted that a third-shift has been added, that will be a lot of stress on a single plant.
IMO, I'd rather have the car built in Australia than in America anyway. We can't build cars all too well with the UAW's involvement, and although I would like to assume that without it we could do better, the realization that the UAW will not likely go away, we may as well keep building them down under.
The General obviously has a plan for the cars, and any guess would signify that they are going to underestimate demand for the car to save their own behinds in case anything goes "wrong" with projections. Generally speaking, that is a far-better idea than building too many and then not sell any (are you hearing me Chrysler?), than build too few, create demand, and then build just a few short of demand every year... Or just build what people are ordering...