So... there are people out there who seriously thought Sasuke was going to say: "I am going to destroy the Leaf?"
How else -could- that encounter have gone? Further... Sasuke hasn't made a sudden "change" in his character. He simply has come to the logical decision that Madara/Obito are wrong in their approach, and need to be stopped.
The kid still as deep psychological issues that need to be hammered out - and there will be plenty of time after everyone has been saved from eternal hypnosis to straighten all that out (Possibly with a good hammering from a Rasengan or two).