Um... I don't know what to say o.O If you look at the photo of Jiraiya's old team below, you can't find
anyone that resembles Pein. Then again, Pein can apparently switch bodies, so... *shrug*
Pic here (courtesy
of blackinque @ AM forums)
Still, Yondaime is dead and from what I know, nobody can revive the dead without giving their own life [like Chio's
jutsu] or bringing back just a puppet [Orochimaru's jutsu], so I doubt it's him. It could be one of the other
two members, though, or some other person that Jiraiya taught in the past [as he did with Naruto].
I guess we'll have to wait and see...