I would imagine that the filler episodes will have to include other characters but would still somehow include Naruto and maybe even Sakura in the mix. The only problem is how they'll do the transition from Naruto after the big fight to him leaving with Jiraya. I'm thinking it'll be something that ties together with the manga and will bring us back to the exact point in the manga as they did before with Sasuke.
Like, for the Manga readers we all knew that Sasuke was never really in the hospital because of some stolen sword and that his jealously and hatred never erupted because of what he saw Naruto do during those racing eps. But somehow the anime was able to make him still get injured still be jealous, for more reasons than JUST being jealous that Itachi wanted Naruto, since that ninja in the filler eps mocked Sasuke.
So I guess these fillers answers my questions for the most part, I imagine that it'll be one or maybe even a few series which will eventually end with Naruto once again being brutally hurt and then Jiraya coming to the hospital to meet with him and thus begin... Otherwise I guess they could end it the way the manga did and just show a whole lot about other characters and then finally throw in the Kakashi series to top it off?
Not sure, but I suppose this could get interesting [img]i/expressions/face-icon-small-smile.gif[/img]