If they finish after 3 years, the last battle would be Sasuke vs Oro, because that's what - as far as we know - the 3 year mark is all about: Oro being able to switch bodies again.
Therefor I doubt that we will only have half a manga-timeline year of Naruto ahaid of us.
I think we will see some sort of training / introduction of the new skills, a little mission, and then, when the 3 years are over, with Akatsuki and Orochimaru making their moves, the real action will start.
[Edit]
Under the assumption that the pictures on narutofan are real:
[img]i/expressions/face-icon-small-sad.gif[/img] I would have liked naruto to wear black + flak jacket.