Mnementh on 13 March 2013
As Kantor said, if Sony or MS would leave console-business, the other would see increased sales. But game-companies have to find new publishing-routes. Surely Nintendo would profite and get more multiplats. Also we would see more exclusives again. Western developers may move partly back to PC. Japanese developers would be largely unaffected by MS leaving, but would probably move towards Nintendo if Sony leaves. The internal studios may be sold, but they would have a hard transition, would lose staff and may work differently under their new boss.
