I don't know... It'll probably be alive for quite sometime after it's ended but I really don't know what there will be to talk about.... Most of the threads will be made by people who are behind on the series, or people who have questions. :shrug:
I mean other than random stuff and roll play, there won't be too much.
It's amazing how so many people can forget about all the thread sections that are not Naruto Manga related. Even when the series ends, there will still be fanboys, and trolls to contend with. Don't think this website will be dead once the manga ends.