I think you should all go and watch episode 56 again [img]i/expressions/face-icon-small-tongue.gif[/img] It all but flashes up on the screen in big yellow letters.
Jiraiya says "Sorry 4th" When he pushes him off the cliff. He also says "Let's see if the power given to you was really meant to protect you..." Who would the 4th give the power too other than his son? Also the fact that Naruto's mum died....
The constant transition between pictures of the fourth and Naruto. The big Rasengan looking thing on the back of Naruto's coat, coincidence? Maybe...