I doubt this is the final fight with Tobi. I suspect he won't die until after the Juubi is revived which will happen. Naruto probably won't be the one to actually kill him. I suspect something causes the Juubi to kill him or something along those lines. I believe that he will succeed in bringing the world under infinite Tskuyomi but Naruto is somehow not affected and has to fight him with the moon in the background.