I think Naruto's training will help end the Itachi Vs Jiraiya thing. Afterall, Naruto's training showed us how Jiraiya's abilities work. Maybe there's still more stuff to know.
And of course people are still gonna remember Jiraiya. Naruto's still actively training in the sage arts and Pein isn't dead yet. Give another 2-3 months...then say something.
Oh, yea, of course there's still more to learn, with every jutsu.
But that isn't the argument, the argument is what Jiraiya could do when he fought Pein.
Could he fight and kill Itachi, that's the argument.
I say no, I've stated the facts and left them out there for people to read.