Watch, there'll be fighting and shit, the Juubi summoning completes, Obito takes one look at it, enters the cliche "what have I done?" moment, and switches sides only to die sacrificing his life (again). The cliches write themselves.
Anyway, I really don't see how the flying fuck Sasuke enters into the equation. As sad as it would be, odds are Naruto and maybe KB are the only ones getting out of the current fight alive(?). Guy has the 8th Gate to drop; Kakashi's fight is "important to the narrative," i.e. he's going to kill or make it possible to kill Obito as his dying action. I mean honestly the series could end with this battle without Sasuke ever entering the picture.
I am a leaf on the wind. Watch how I soar.