I think after he's done with the series, he should make little mini episodes with fights between ANY characters in the show whether or not they ever met or if it would make sense.
Sarutobi vs. Minato
Kabuto vs. Orochimaru
And he could make mini-episode fights that make a little more sense
Like, Sasuke vs. Sakura
Or Orochimaru vs. Anko
Zabuza vs. Haku
There doesn't have to be plot (or maybe some minimal plot development within the mini-episode would do) primary focus would be on characters battling it out.
And there could be different versions of fights:
Sasuke vs. Naruto
Sasuke vs. Bijuu Mode Naruto
Sasuke with Curse Mark vs. Bijuu Mode Naruto
Sasuke Curse Mark level 2 vs. Naruto without Bijuu Mode
^Only that alone right there covers 4 weeks if the mini-episodes follow the same schedule.