Naruto Chapter 578

[DB_Hunter]

Kabutoro can't summon Shisui, otherwise he wouldn't have gotten so happy at the thought of seizing Itachi's crow with Shisui's eye in it. The most likely thing is that he will summon their parents in an attempt to throw them. Itachi won't have a problem killing them again, but it might be enough to sway Sasuke as all he wants to do is talk to the family he never had. That could lead to conflict between the parents and Itachi and ultimately (and ironically) Sasuke having to fight his parents has he decides all his family are dead and that his brother is right in what he is doing thus deserves to be helped. As Sasuke 'kills' his own parents he realises the sacrifices that Itachi had to make were correct for the greater good, hence they end up defeating Kabuto. As Itachi see's this realisation dawn upon Sasuke he makes peace and his soul departs, leaveing Sasuke to join the battlefield on the side of Konoha.

Edit: And knowing Itachi, he probably has already placed Kabuto under genjutsu without the fool realising.