Well, there isn't annything to do after the war is over, and it's more of just one huge battle than an actual war. They should streach it out some more. I wouldn't be surprised if Naruto lasted less than another year. The rate of ressurected Ninjas that Kabuto raised getting knocked out is pretty fast. The've already taken out about a third of them. Once Madara is defeated there is no where else to go. Then again, in DBZ every time they took out a major enemy (Freeza, cell, etc) then they begain another story all together; maby they'll do the same with Naruto. But the series has been around since I was in midle school, and as powerful as naruto has become, I doubt that they'll bring about another enemy or group of enemies.
Maybe they'll do a story in the same mangga universe only set 20 years or so in the future? (But that would probably suck)