Well I have been throwing this idea around on the forums for a little bit now, that at some point Itachi will break free of Kabuto's control and this will have a important impact on the story.
One of the great things about Itachi is his ability to grasp the big picture hence why he is able to plan several steps ahead as he did with Sasuke's implanted Amatertsu or implanting some of his powers in Naruto. He has clearly show a capacity to surpass all expectations put before him so the idea that hes just going to be some doll for someone like Kabuto doesnt add up to me.
We know that the connection between the summoner and Edo summon is the chakra they use for the summoning and is also used to force their will upon them. However as we have seen as of late with Zabuza /Haku and even Hanzou the Edo summon has the capacity to resist the will of the summoner.
I feel somewhat sure that at some critical point Kabuto plans to use Itachi against Sasuke to weaken him enough so that he can try and take him over. However I think Itachi has already anticipated this since his resurrection and has a plan of his own.
Since its already been explained the ways to deal with Kabuto's mass Edo Tensei is using Genjutsu on the user to end the summon I think this is where Itachi comes into my plan. Since we know Sharingan Genjutsu does not require hand seals I think at some point Itachi will use his Edo Sharingan on Kabuto placing him under multilayer Genjutsu similar to Genjutsu battle with Sasuke.
My feeling is that since Itachi did not have a clean heroic death this will be his redeeming final act showing him finally able to act on his true desires and wishes. Madara had a chance to tell Kakashi and Naruto about Itachi's past but they have not really had a chance to confirm this. With the war ongoing Kakashi hasn't had time to grill the Leaf elders about this.
I think that at whatever point Kabuto gets near Itachi he will enact his subtle Genjutsu. The Genjutsu will be so flawless Kabuto wont notice until later and when he tries to break it and puts Itachi back under total control. It will appear Itachi pushes Sasuke into a corner and Kabuto will get ready to take advantage and just when it looks like hes about to succeed it will turn out to be a Genjutsu and he will be forced to end Mass Edo Tensei. Edo Itachi will begin to crumble and fade away and offer Sasuke one last piece of advice.
My feeling is that this will only effect the Edo summon bodies currently summoned some how permanently making them unable to summon again. So he will still have access to the mystery coffin but not to his army of Edo summons.
In this way Itachi will be able to have a truly epic heroic end proving to Kakashi and the others that Madara's tale was based on truth then Itachi truly ends as Hero. This is Itachi's purpose here in his final act to end the current Edo Tensei and I cant think of anyone better to do so.
Your thoughts & ideas?