A part 3 is being very anticipated right now. And the way I see it, and many others will agree, Naruto being the strongest man on earth at that point in time will mean that nobody will even consider stepping to him. And if so, that may only be Sasuke at the end of the series if they fight for Hokage.
Or maybe Part 3 will have a much, much lesser emphasis on fighting... which I totally wouldn't mind. What do you think?