The CNN article covering GM's decision to kill the Oldsmobile brand mentions:
"'Once GM began relying more on sharing components, and virtually entire cars, among different brands, Oldsmobile began to suffer from a loss of identity,' said Ken Gross, an automotive historian and columnist for Old Cars Weekly."
Hopefully Saab will not share this fate, but in light of the very un-Saab 4WD vehicles in the pipe, it seems like a possibility.
John