Bob at Cars!Cars!Cars! predicts that GM and Ford will have to merge to survive. This is an interesting idea, and makes a certain amount of sense, from the outside--the last stand of the All-American Manufacturing Giant. However, to pull it off, they would basically have to go bankrupt first. GMF would need to be lean and mean--the combination of GM and Ford's best products, not the combination of their legacy costs and union contracts.
I see another likely merger between Ford and a foreign competitor, such as Honda. Ford would be a good acquisition for a company that wanted to buy its way into the light truck and commercial vehicle market. Honda-Ford would have a lineup of world class compact cars, light trucks, and commercial vehicles. The problem is, how would Honda handle the UAW?
As a side dish, maybe Delphi and Visteon would merge too--Delpheon. Quick, somebody trademark that.