I think the main battle are almost as listed above..however Sasuke's willbe against Itachi- Sasuke( im no sasuke fan boy ) is whats going to cause Akatsuki problems when they go after Orochimaru. Becaseu Itachi will not be able to fight, or focus on the real fight against Orochimaru. Naruto will be concerned for sasuke there is very good liklyhood that we are going to see a battle royal. a seroius one. many people will die.

Orochimaru, is a jinchuriki( this is when he left the akatsuki IMHO) - the 8th demon Naruto will defeat Orochimaru....or rather the kyuubi will defeat the 8 headed snake
the Kyuubi is going to be changed by naruto as well, so they will defeat Orochimaru-sama. There is somewhat foreshadowing to Orochimaru being a Jinchuriki... via morino hibiki

thats my prediction.