I think that Naruto would have sought vengeance against his criminal brother for killing his clan. Even though Naruto would have initially been better than Sasuke, Sasuke would have eventually surpassed him, pushing him to seek out one of the Legendary Sannin in order to get more powerful. Naruto would kill his mentor and form a team to track down his brother. Naruto would eventually get his revenge, but in doing so, he would learn the truth about the Leaf Village's history and seek vengeance against the Village for the wrongs committed against his brother. Meanwhile, Sasuke would become the village hero after saving the village from the powerful Akatsuki leader, Pein. Akatsuki's real leader would then reveal himself to the leaders of the shinobi world and begin the Fourth Great Shinobi War. That pretty much sums it up.