No one around here needs to be reminded that the fate of GM is a great concern to metalcasters — as are the fortunes of Ford and Chrysler. Of the three, however, GM is the one that has indicated it plans to continue producing cast products in house, in significant volumes.  I've not read anything that analyzes the stakes in terms that are specific to metalcasting, but this analysis in the Fort Wayne Journal Gazette, about the GM Powertrain plant in Defiance, OH, lays out some possibilities.