first of all, they never say naruto was indeed a senju. He just resembled the 1st in his way of thinking.
What may follow this great reveltaion?
obviously, naruto will try to break this hatred thing bla-bla...but onto near future...I can fell a battle or encounter between naruto and sasuke is about to begin. Raikage gets dispatched imo. Since naruto knows that sasuke is in the summit, he'll try to speak to him. To make things clearer.And then madara will get in the way and order already crazy sasuke to attack naruto.
Then, itachis' gift...Imunnity to the sharingan. Why it must be tsukuyomi, susanoo or something as wierd as that? Itachi wanted Madara dead, so he need's naruto and sasuke to work together. As he knew madara would get his hands onto this, I think he wnated naruto to be immune to the sharingan.
If not, madara would easily control him but wait...can a bijuu be controled if it has a jinchuuriki? As they said with the 3 tails:"it was an easy match beacuse it didn't have a mind to control it's power". So that was why madara could control kyubii, that's why bijuu must be sperated from jinchuurikis in the plan of akatsuki.
As for kages, they'll be giving more and more revlation about danzo and perhaps they may try to help raikage. Though i hope they don't.
As last words, how does this sound: "Sage art:Amaterasu-rasenshuriken!" Wind+fire, madara's ass get kicked/burnt and cut cellularly.Check how did kakuzu used both wind and fire together. Sasuke + naruto vs madara.
Too, have we seen madara's actual body,i mean during the whole part 2. Cause i've never seen him use his right eye. Could he be splited in 2 like zetsu?
fell free to comment...