“I haven’t even told Steven or Harrison this,” Lucas told Fox News. “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.” Harrison Ford told USA Today in April that he also might consider a fifth installment of Indiana Jones.
http://www.slashfilm.com/2008/05/16/lucas-has-idea-for-indiana-jones-5-spielberg-labeouf-and-ford-dont-rule-it-out/