They did back in the day. I found something but looks like it doesnt help though.
http://www.dbzgtlegacy.com/dbzlam.shtml
Q. - Who is directing the movie?
A. – Roland Emmerich, the director of Independence Day, Godzilla, and Day After Tomorrow.
Q. – Who is writing the movie?
A. – Tedi Sarafian, screenwriter of Terminator 3.
Q. – When will be movie be out in theaters?
A. – 2006 (probably summer, since most action blockbusters are released then).
Q. – Does Toriyama have anything to do with it?
A. – DBZ creator Akira Toriyama was hired as the film’s consultant but wanted too much control over it so FOX made him sign a new contract, which basically gave him the boot. :-(
Q. – So, who’s distributing it?
A. –20th Century FOX.
Q – MPAA Rating…what’s it gonna be?
A. – Not rated yet, because the movie has to be finished before the MPAA can give it a rating. But FOX is shooting for a PG-13.
Q. – Hm, who’s doing the special effects?
A. – It was supposed to be George Lucas’s ILM company, but rumor says they’ve bailed out.
http://www.themovieinsider.com/m685/dragonball-z/
that website says 2008 so who knows.