I've seen a few different articles where Fulmer has stated that he doesn't want to coach football until he dies. I even saw one where he speculated that he would retire within the next five years, but I think he wants to go out on top. If he can get us to another NC, he's out. I think that he might even go after a SEC title if he doesn't see a promising nucleus for the next season.
I don't think he's gonna just up and randomly jump ship, but I also don't think he'll stay nearly as long as B Bowden or Joe Pa.