Sasuke won't betray Naruto - they were never on the same path to begin with. He's got his own agenda, and if Naruto is going to be an obstacle, he'll knock him out of the way.
I'm sure there was an interview where Kishimoto said he wanted Sasuke and Naruto to go down different paths from the very beginning of the manga. The irony is both essentially want the same thing. The major difference is while Naruto wants to change and understand people, Sasuke just wants to do everything by force.
It's kinda obvious he would do this despite his objectives not being clear, what he will achieve by killing Naruto? Obviously not becoming kage which was kinda obvious he would not be kage due to that reactions earlier.
Probably he's just acting like a emo kid(with a plan) again, the whole flashback of Itachi on Sasuke's mind i always thought it only increased his hatred towards the village and i got surprised when he said he was going to protect it and almost 100% knew it was bad writing since he didnt even thought about the village.
Also overkill on SS after Sasuke's second betrayal.
Killing Naruto is probably how he thinks is the easiest way to kill the old system. For all we know, if he's the strongest guy around, he doesn't need to become Hokage, he could be whatever autocrat he wants to be (daimyo?).
Sasuke doesn't seem to hate the village anymore, he just hates the whole system that turns everyone into enemies. Kishimoto has just shifted his goals so that it matches Naruto's, probably to highlight the contrast between how they're willing to reach that goal.
Edited by Nefertieh, 17 July 2013 - 12:53 PM.