Wow.. And I thought that I came up with long stories.. LOL Just kidding...
You do have a point my above.. But my mind is just telling me a little something.
This is STILL Kishi we're talking about. I thought that his reason for making Naruto is to make clear that anything can be done as long as you believe, be strong and to NEVER give up.
That's what Naruto will do with Sasuke. As long that boy is still in out of the reach of Konoha, Naruto will try to get him back.
I can see it happening though, Sasuke becoming an aka. But, Sasuke isn't an idiot (That's what Kishi's making clear) If Itachi tried to get him away from Madara, then Sasuke should use his (now mentally ill) brain and know that Madara isn't good.
What bugs me is, that Madara doesn't need Sasuke. I mean c'mon. Madara has the eternal MS, could like live forever, has the power himself to get all the tailed-demons, and can kill somebody with just one look of his Sharingan. Now tell me what part can Sasuke play in this?
Obviously Madara didn't necessarily need another Uchiha. Or else he could've get one of those he slaughtered. Or maybe even Itachi. But Sasuke? Come on, compared to Madara, Sasuke is at the same level as Konohamaru.
Maybe because we're expecting that Sasuke is going to turn out aka, he's NOT going to turn into one. You never know, maybe Kishi decides that now that Sasuke knows the truth he's gonna flee and return back to Naruto. (I hardly doubt that:P)
OOOORRRR, Sasuke's gonna defeat the aka from the inside. Proceed with the same mission that Itachi began.
I'm sure that Tsunade knows about this, about Itachi's mission. And maybe that's why, Tsunade could give him a full pardon when or 'if' he gets back.