As shown on Planet DragonballUPDATED: In a related story, it looks like the live action movie will also finally be happening, though it's not quite what everyone had expected. The movie in the works focuses on the end of Dragonball, not Dragonball Z. It'll most likely take place during the final fight between Goku and King Piccolo, leading up to the fight between Goku and Piccolo Jr.
As shown on Installation 04 blog
