Well, after all, you could say that everything till now is just the beginning of the series.
The end of the Sasuke chase-arch marked, imo, the change from prologue to chapter number one.
At that point, Sasukeīpersonality and goals have been exposed completely.
Also, the Akatsuki have been declared as the real enemies, being told to Naruto by Jiraiya.
And now, at the point of the Naruto vs. Orochimaru battle, i see the beginning of Narutoīs real story.
That fight has to deliver something important story-wise to us (and imo, Naruto will loose the Kyuubi, but weīll see about that).

And i wont complain about Naruto taking a lot of time before getting finished, because i love long series.
Thatīs why i loved Dragonball, thatīs why i loved Hunter X Hunter, and thatīs why i love Eureka Seven (although thatīs not a so long series, unfortunately).