Fury will have juristiction when he turns 18 but I don't see him pressing Peter into serious action right away. As has been confirmed in Ultimate Nightmare, Fury has a number of enhanced humans stashed away as operatives on call. Given that Peter in no way would be suited to military or paramilitary actions that's the sort of role I see for him under Fury. Especially considering the PR issues around his careerSpider-Man. Spider-Man will never be in the Ultimates, but I see Peter serving as an espionage agent (he did manage to tail Fury unnoticed for quite some time - not an easy feat, especially for someone with no training) used in shadow ops, thiough probably not for anything that requires lethal force, not at first at least. Fury's got more than enough military personnel for those kind of ops. But the more I think about it a SHEILD trained Parker is a pretty sweet concept. Proper trainingin the full use of his abilities is something that as far as I know Spidey never got in 616 and would leave Peter a whole lot more able to handle hislife as Spider-Man. Either way this is a long way off, but hopefully Bendis will be on it still at that point, I'd really love to see what he'd do with it. I'd wager around issue 150 or later given the speed at which time appears to be flowing.