Indiana Jones 4 filming 2005 ?
He also said, that he expects to direct a political movie (that he didn't want to talk about), after directing "Indiana Jones 4". It's very likely, that it will be "Vengeance". A movie about the terrorist attack during the 1972 Olympic Games in Munich (Germany), where Israeli athletes were kidnapped by a group of Palestinian militants ( 11 Israelis lost their lives).
Frank Darabont's script has been taken by George Lucas, to get re-written by some (still unknown) author. So we don't know, how much of Darabont's script will remain in the movie.
With the usual production time at such movies, it should be possible to see Indy back in action, in late 2006.