I don't believe that Sasuke will attempt to gain the Rinnegan, He has too much pride in the fact that he is an Uchiha, having to rely on Senju cells to make him stronger would be admitting that the Uchiha are inferior, the reason Madara gained the Rinnegan is because he no longer had any pride in being an Uchiha since to him the Uchiha abandoned him, and Obito is a similar case.
Also if Kishi is going for a parallel between Naruto and Sasuke's fight with Hashirama and Madara's fight, no Rinnegan would be best as Madara did not get his Rinnegan until years later possibly after Hashi's death, and that is another reason against Sasuke gaining the Rinnegan Madara said that he didn't obtain the Rinnegan until years later and just having Senju DNA dose not guarantee that you will obtain the Rinnegan, as Danzo had both Senju and Uchiha DNA and yet he did not have any Rinnegans.
Technically there has been another arc, we are now in the second arc of the war the Ten-Tails Revival arc.
Personally I don't think Naruto needs to confess, after 631 you'd have to be an idiot to not see that Naruto is still interested in Sakura romantically.
I think he will use it because look at the lengths he went to get more power , he didn't rely on his power solely alone , he also used the power of the curse mark when need be , if the Rinnigan means him getting stronger , he wouldn't care . Pride or Not .
Edited by Superman333, 29 August 2013 - 09:01 PM.