As had been suspected previously, George Lucas will not be involved with Indiana Jones 5.
As much as Frank Marshall and Steven Spielberg love and respect the man, it does make sense to move on.
It looks like things are getting more serious now, as producer Frank Marshall is readying things on his end before Steven Spielberg jumps behind the camera again.
Lucas has a very close relationship with Steven Spielberg and has been heavily involved in five previous movies in the franchise.