There is an older thread on this topic that included an article from AICN which was written at a time when the script was finished and connery, ford and spielberg (being very happy with it) were "ready to go". Alas, Lucas had put in his lastminute veto and took over rewriting the script until HE is satisfied with it - needless to say the original author threw the towel at that point and the preparations for beginning the project came to a screeching halt.
Searching through the AICN article database to find the article (posting all indy4 related AICN links I'll find in the process):
INDIANA JONES and a total lack of Nazis will be coming to a theater someday!
Found another article on the same topic [source: spielbergfilms.com]. Here's an excerpt:“By all accounts of those who have worked with [Lucas], he isn’t one to multitask when he’s making a film. That left Spielberg and Darabont to work out the script. Imagine Darabont’s joy when Spielberg pronounced that he liked Darabont’s draft, except for some quibbles with the third act. Darabont reworked the screenplay, and a few weeks later—last fall—Paramount was told that Spielberg would shoot the picture in July 2004.”
So according to the article, the script was Darabont and Spielberg’s baby, unlike the previous three Indiana Jones films (in which Lucas, Spielberg and the screenwriters all toiled together). It’s been reported numerous times that Lucas devised the story for the new film, yet the Esquire article wraps up by stating that “the official story is that the project is not dead and that Lucas will come up with a storyline himself.”
I’m not sure if this is stating that Lucas didn’t conceive the screen story for Darabont’s drafts at all and he will be crafting a new concept himself from the ground up or if this means Lucas will be drafting a brand new script himself (God help us). Lucas’ “storylines” for the Indy films (i.e.-stories for the films, but not the actual scripts) have been great, but his work as a screenwriter, as history has proven, is not even a shadow of Darabont’s talents.
Either way, Esquire’s article is unclear whether Lucas plans on crafting a new story or drafting a new script personally, but the article does end with a couple of notes of doom.
According to someone allegedly close to Spielberg within the DreamWorks fold, Spielberg won’t be too heartbroken if the film doesn’t ever come together (Spielberg has promised in the press that it will happen still), and as Esquire tells it (for what it's worth) “many in Hollywood are skeptical that it will ever happen.”
“[Spielberg] liked the idea of it, but I don’t think he was in love with doing it,” the fellow “DreamWorker” told Esquire.
If true, this is never a great way for Spielberg to head into a movie and his filmography, the Indiana Jones series and Indiana Jones fans deserve more than that. Spielberg has throughout his career been infatuated with many a concept. We’ve all seen how many scripts he courts but never commits to, wisely in the end. When Spielberg isn’t completely in love with working on a film, he stumbles with works like HOOK and THE LOST WORLD (which he “always, sort of wanted to do”—a very non-committal reason to shoot the film from Spielberg himself).