Quote Originally Posted by DB_Hunter View Post
Pretty sure its going to be some sort of ability, as didn't Itachi say he has given Naruto some of his power when that crow went in? Whether it is something Naruto has control over or if it is an event/trigger based ability remains to be seen.
When you put it that way, I want to think it's the ability of the Sharingan to control the Kyuubi.