Sakura-I believe her final moments will be in sacrifice to naruto/sakura whether that will only be somehting like neji taking a fatal blow to performing lady chiyo's technique, i just can't see her surviving, i mean to surpass her mentors and that is one key step in surpassing them.
obito- either using rinne tensei for good or evil. or maybe just curbstomped by the good guys.
Gai/lee we have to see teh 8 gates and to see them the user needs to die. I don't expect us to have had heard so much hype about it and not see the results of it. we didnt see it in rock lee and pals so we have to see it here