Well my point is that he started the whole obsession with reincarnation and becoming a perfect being ,because he wanted to revive his parents or because he didn't want to die like them
Remember that Jiraiya said that Orochimaru became evil probably because of the death of his parents. And remember that scene with Orochimaru finding a white snake skin with Hiruzen.
It would be realistic to think that they would in the end find peace. If not what will be the point of the series? But I don't think that this war arc will be the last. With Orochimaru back, I think Naruto will last at least two or more years.