No matter what happens Jiraiya is seriously screwed would be nice if he could manage to escape or get back to the leaf before he dies but honestly I want him to die like this it suits him. I doubt Itachi could beat Pein, because even if they all share the same points of view I don't know if using genjutsu on one or all of them would work. Then again we've only seen then again we still don't know much about Itachi because we have only seen him use all of six techniques but if his genjutsu could work on Pein like that it would be pretty lame.