already has ending in mind, so story is "racing headlong" that way

At the end of an article published in the Saturday evening edition of the Asahi Shimbun paper, manga creator Masashi Kishimoto revealed that his Naruto "series is rising towards its climax" at its current point. He added, "How the story will end has already been set in my mind, so the story is just 'racing headlong in that direction.'"

Kishimoto has been serializing the ninja manga in Shueisha's Weekly Shonen Jump magazine since 1999, and Shueisha published the 60th compiled book volume in Japan last month. Viz Media will publish the 57th volume in North America next month.

[Via Manga News]

Update: More background information added.