It's no secret that Harrison Ford is a Indiana Jones fan. In fact if I played the whip cracking archeologist I would be a fan of my own work as well. Even with elements such as jumping out of a airplane using a yellow raft to land correctly, or surviving a mine car roller coaster ride to making it through a nuclear blast because you were tucked inside a old style fridge, these are the crazy antics that make Indiana Jones, Indiana Jones. Harrison has gone public before and this time there is no difference:
"Steven Spielberg, George Lucas and myself are agreed on what the fifth adventure will concern, and George is actively at work."
Hopefully they also agreed that Lucas will only write the fifth film. Which is all he should have ever done. Lucas is a Writer, that's it. Lucas is no director, which is why I believe the second trilogy of Star Wars films were not as good as they could have been. Anyway that's an entire different article. In short, Lucas, stay with what your good at!