I'm honestly not sure any newer movie will be regarded as a classic the way Star Wars is now. New films, for all their awesome spectacle, are just too commonplace nowadays.
Even Avatar, the highest grossing movie of all time, probably won't stand the test of time. Does anybody even talk about Titanic or The Matrix anymore?
I think long-running franchise films are a bit different though. We're still here talking about the Star Wars
prequels and the Next Generation