at the shortest lamest case possible, we still have 2 major things to deal with.

A. Sasuke and Itachi,
and more importantly, Akatsuki and thier deal with Naruto.

those two alone can have to carry us for about two years, and with all the minor charecters going around (kakashi, kabuto, lee) and the other charecters (gaara, neji, hinata, shino, shikamaru) we have about three - four years left in naruto..

and that's considering having no new issues to deal with..