Okay, as of what we've seen so far in the manga, a Sasuke vs Naruto all out fight would be really close. It will probably depend on wits and who uses their strongest techniques first. Think about it;
As an overall ninja with a variety of ninjutsu, genjutsu, taijutsu and intelligence, Sasuke is better. He will definitely own at the start.
Sasuke has 2 unavoidable techniques in Amaterasu and Kirin. Now, a great ninja with good defensive abilities, like Kakashi, The 2nd or 3rd would probably find a way to get around these techniques, but Naruto, as good as he is, can't. He would get raped by Amaterasu or Kirin.
However, if Naruto is smart and summons Gamabunta, and/or Hiro and Ken, along with Ma and Pa toads, even Gamakichi, I don't see how Sasuke will win, even with Susanoo. Also, Manda is dead. Fighting all those toads definitely is tough for any Shinobi, and thus Sasuke will get raped here.
Rasenshuriken is as strong as Amaterasu, but is avoidable. Sharingan Sasuke will probably dodge it unless he is trapped/ off balance by Shadow Clones.
Also, Naruto has the Kyuubi, and Four Tails Naruto will destroy Sasuke imo.
Then, there is whatever technique that Itachi gave to Naruto. And it WILL be Naruto's technique in the same way that Itachi GAVE Amaterasu and Susanoo to Sasuke.
There is more in Naruto's favor. Therefore I predict Naruto will win.
Cheers!