GM plant closures - playing the guessing game

There's little doubt that GM will perform some much-needed plant closures in the very near future, but it's only educated guesswork at to which plants may be shuttered. The Detroit Free Press takes a crack at in the linked article, and the plants they list are ones that are being talked about by plenty of others as well.
There are a huge number of variables that go into such decisions, including not just current data but also some deep looks into the crystal ball for insight on vehicle trends. High on the list of desirable factors has to be flexibility, since it's unlikely that the fast rate of change in market trends will slow in the near future. Certain plants have unique capabilities, such as the casting and engine assembly operations at Spring Hill, and those have to be taken into consideration as well.