Basically I can see Naruto taking the classic storyline of many older manga:

1. Buddies grow up together
2. One of the buddies turn bad while the main buddy remains good
3. Bad buddy strives to defeat good buddy
4. Good buddy hesitant to beat bad buddy
5. New evil stronger than 2 buddies comes along
6. Buddies become good friends again and defeats new evil
7. Friends forever, blah blah

Sounds familiar?
Shulato anyone?