As so little about this movie has been confirmed at present, there is very little to say here.
There are many websites which contain alot of information about other movies, and they are usually accurate. Unfortunately, in the case of Artemis Fowl, they have clashing views, and so, things can get confusing, as alot of it is wrong. The situation is so bad that IMDb (the largest Internet Movie Database) have taken Artemis Fowl off their website entirely, as it has been up for so long, with no concrete information available. Wikipedia then followed suit, claiming that there was more rumour than fact on the page, and so, should not be present in an encyclopedia. The page has now been restored, but contains very little reliable information.
As far as I can tell, this is how things stand with the Artemis Fowl movie at the moment:
Studio: “Miramax Films” and “The Weinstein Company”
Director: Jim Sheridan (Read the article.)
Production Companies: Tribeca Films (Robert De Niro’s company).
Writers: Jim Sheridan and Eoin Colfer are both working on the script.
Source Material: Eoin Colfer (“Artemis Fowl,” 2001)
Actors: Aidan Mitchell has shown an interest in the role of Artemis. (Article here on Unison.ie).
For all the rumours about the casting, ranging from very possible to utterly insane, check out our Movie Rumours page.