George Lucas says a fifth Indiana Jones movie is a distinct possibility:

“I haven’t even told Steven or Harrison this,” he said. “But I have an idea to make Shia [LeBeouf] the lead character next time and have Harrison [Ford] come back like Sean Connery did in the last movie. I can see it working out….”

Maybe so, but let’s hope it doesn’t take another 19 years to make it happen. In 2027, Harrison Ford will be 85 years old, and Shia LeBeouf will be 41. And the movie would have to be set in 1976.