I will be surprised it it ever happens,
WoW is still the number 1 mmo. But the game is past its half life, a movie of WoW calibre will take at least 2 years to make, In which WoW will be well into its next expansion and loosing even more subs
WoW fans will be less then and any non WoW fans will think it is a LoTR rip off, and will probably not watch it
So I will be suprised if it actually gets off the ground
Now if it was made CG, it would massively reduce costs on actors and sets, and there latest CG sequences are fantastic (SC2 trailer being an example)
considering the movie was announced years ago. with the game story is constantly changing, so the question will be how will the movie influence the game, will it be a retelling of Warcraft or anything up to current lore or a side story, too many questions and no answers is another reason why I have lil faith in this making it to production