I think you may be a bit too generous to Sony on the matter Lafiel. It is indeed an optimal financial move, and a wise one, but I think its safe to assume its one they'd rather not have done if they could have helped it. This isn't Sony exercising pro-active strategizing it's them reacting to severe financial set-backs and losses. In other words, this isn't Sony pruning a tree to encourage growth of healthier branches, its them cutting off their foot to escape a bear trap.
I'm also not exactly sure where the basis for your statement that Sony is any less adept at producing the cell vs Toshiba comes from. Perhaps Toshiba does have more experience in production, but its relevancy to Sony's decision to sell off the plant is pretty thin and a dubious excuse.
In the end, whether this is a good move or not, it was really something Sony was forced to do.
