What hasn't been revealed yet in the manga is, What did Itachi give Naruto as a parting gift?
1. Itachi gave Naruto a deterrent of the Mangekyo sharingan.(most likley Amaterasu)
2. He gave him a certian power of control against the nine tail beast.(since the crow went into his mouth, were the key is also and the Mangekyo Sharingan is said to control the Nine tails)
3. Itachi gave him the knowledge of the Sharingan and made it possible to counteract the sharigan through the control of the nine tails.
I hope Masashi Kishimoto soon reveals what Itachi gave Naruto, because it is just irking me.
Please post some comments to open up some more perdictions about this.