You never know; someday Disney may buy Universal and Columbia (or heck, all of Sony) and fold all their respective IPs into its mega-multiverse. E.T. and the Close Encounters aliens will get some Jedi training and team up to battle Galactus or something.
E.T. is already an official part of the Star Wars universe. You can see some of his people in the Galactic Senate during The Phantom Menace.