I used to think Jiraiya was not really dead. That he might have survived and would apear one day. Just a wishful thinking. But seriously major characters have to die for the development of story.
The chance of Jiraiya having been revived by Nagato is zero. Nagato couldn't have done that after that attack on Konoha. He didn't even revive Yahiko, his closest fiend.
The chance of Jiraiya being revived by Kabuto is also slim. Kabuto already said he didn't have the DNA. After all, we have seen enough edos as of now. Let Jiraiya rest in piece.