Jiraiya deserves a LOT of credit. he planted the seed of goodness in Nagato, as well as led Minato and Naruto down a great path.
however, Naruto has already surpassed Jiraiya even in that aspect.
he changed Neji
he changed Gaara from an evil jinchuuriki into a loved kage which has a direct effect on thousands. Gaara's speech united the shinobi army too.
he changed Tsunade from a bitter old woman into a hokage which again has a big effect on thousands.
those two have a direct impact on the kage summit.
he also has done some good in changing Oonoki, some through Gaara and some through his clone.
him and Bee have done some work in changing A into a more trusting and altruistic Kage, when he was mostly a selfish and arrogant one.
he got Nagato to revive the whole village, and Konan to believe in him as well (who almost killed off Tobi btw, and Nagato using rinne tensei sabotaged Tobi's plan in some way)
not to mention the work he's done with the bijuu. he might have gotten rid of all their hate for good, which is pretty huge considering how much they are hated and feared by ninja.
so I'd say he's done quite a bit.