Contactmusic.com ran a short story about George Lucas being a bit gun-shy with the upcoming release of Indiana Jones and the Kingdom of the Crystal Skull. Apparently, he's anticipating the same sort of reaction he got from many fans when he released the Star Wars prequels. To quote The Maker from the article:
"We're not gonna have adoring fans sending us e-mails saying how much they loved the movie. We're gonna have a bunch of angry people saying, 'You're a bunch of a**holes, you should never have done this. You've ruined my life forever.'"