Personally I'm hoping they stay away from a live action idea and go rather into the CGI style purely because they'll be able to deliver a better feel in terms of how things should look, perfect examples here would be: Warhammer 4000 Space Marines, Mass Effect Paragon Lost, Final Fantasy The Spirits Within, Final Fantasy Advent Children just to name the most obvious, there are a few more obscure ones but these help my point better.
This would also mean they have less restrictions on what *Can* and *Can't* be done realistically without needing to compromise any of the lore and game play style we've come to enjoy over the years. I know some films that have come out of the gaming world haven't done too badly i.e Mortal Kombat, Tomb Raider, Mario Brothers, which on their own were more platform based without any real huge background or lore to support them unlike WoW which currently has Vanilla followed by 4 expansions all of which have their own history's, lore and story spread through several novels as well as specific story lines that have in some cases been expanded in the game.
Can't really add Resident Evil to this as it's kind of grown on it's own although the latest one (Retribution) could of been so much more then your simple *We must clone/bring back Alice so she can kick the crap out of everything again* scenario, but to be fair there are books supporting most of what went into the film before and after production of the initial cinema release in 2002.
But Resident Evil and similarly Lord of The Rings/The Hobbit don't have half the races that make up even half of one faction i.e Horde/Alliance. Does this mean when it comes to WoW that we'll have to miss out seeing many of the races because they can't afford such a budget to hire that many people to cover all the basic races? How about mounts both ground and flying, how about pets and companions, I know of course this kinds of things would most likely be animatronics but why make a simple job harder just so you can cast a specific role with a big budget actor when having people do the voices etc would workout so much more appealing to the viewing public in general.
As the OP has already stated, a lot of us (myself included) have been waiting many years for this, ever since I saw the first cinematic upon launching WoW back in vanilla, I thought this could be a really cool concept if ever taken to the big screen, even more so now when you look at MoP's initial trailer and how the Horde/Alliance land on the isle of Pandaria. The smoothness in which things are now being rendered is so much better then it was back in 2004 when this all started and so having a bunch of actors come along playing the roles would just ruin the experience.
This is all just my personal opinion but it's been formed since the day I first started playing and has only gotten stronger in this particular view as the years have gone on and I've seen how other games/books/comics have been hashed together like Dungeons and Dragons in the hopes of just bringing in a bigger audience due to a celebrity name rather then the story itself and it's own merits.
Hell if done as CGI not only would it be legend... Wait for it... DARY! But it could become quite an awesome series when you consider how many books of lore there actually are currently:
These books were published using the WARCRAFT trademark.
1. Day of the Dragon by Richard A. Knaak
2. Lord of the Clans by Christie Golden
3. The Last Guardian by Jeff Grubb
Of Blood and Honor by Chris Metzen (unnumbered, not technically a novel)
Despite being clearly numbered, The Last Guardian is set years before either Day of the Dragon or Lord of the Clans. These novels can be read in any order, as all contain spoilers for the events of Warcraft: Orcs & Humans and Warcraft II: Tides of Darkness.
War of the Ancients
The Well of Eternity
The Demon Soul
All by Richard A. Knaak
Though acting as a prequel to the events of all Warcraft games and novels, this trilogy involves characters from Day of the Dragon traveling through time, and thus has spoilers for that novel and Warcraft III: Reign of Chaos. Though reading Day of the Dragon and Reign of Chaos are helpful for understanding events and characters, they are not required.
The following novels were published under the WORLD OF WARCRAFT trademark (this is the publication order):
Cycle of Hatred by Keith R. A. DeCandido
Rise of the Horde by Christie Golden
Tides of Darkness by Aaron Rosenberg
Beyond the Dark Portal by Aaron Rosenberg & Christie Golden
Night of the Dragon by Richard A. Knaak
Arthas: Rise of the Lich King by Christie Golden
Stormrage by Richard A. Knaak
The Shattering: Prelude to Cataclysm by Christie Golden
Thrall: Twilight of the Aspects by Christie Golden
Wolfheart by Richard A. Knaak
Jaina Proudmoore: Tides of War by Christie Golden
In spite of the trademark and the slogan "based on the best-selling video game", most of these books are not set during the events of World of Warcraft. Cycle of Hatred is set in between Warcraft III: The Frozen Throne and WoW; Rise of the Horde, though told through a series of flashbacks just prior to World of Warcraft: The Burning Crusade, is set almost a century earlier; Tides of Darkness and Beyond the Dark Portal relate the events of the Second War. Night of the Dragon is set prior to the events of World of Warcraft: Wrath of the Lich King and reveals the current state of the black dragonflight, and Stormrage is set after the defeat of the Lich King but shortly before those of Cataclysm. World of Warcraft: The Shattering: Prelude to Cataclysm also takes place between Wrath and Cataclysm. Rise of the Lich King deals with the events of the Third War. Twilight of the Aspects takes place during the events of Cataclysm
Chronological order: Tides of Darkness, Beyond the Dark Portal, Arthas: Rise of the Lich King, Cycle of Hatred, Night of the Dragon, Stormrage and World of Warcraft: The Shattering: Prelude to Cataclysm. Rise of the Horde is set before all of these, but takes the form of an extended flashback (from just before the beginning of World of Warcraft: The Burning Crusade), so it could be argued to be read between Cycle of Hatred and Night of the Dragon.
Rise of the Horde
First War (Warcraft: Orcs and Humans)
The Last Guardian
Second War (Warcraft II: Tides of Darkness)
Tides of Darkness
Day of the Dragon
Invasion of Draenor (Warcraft II: Beyond the Dark Portal)
Beyond the Dark Portal
Lord of the Clans
Third War (Warcraft III: Reign of Chaos and Warcraft III: The Frozen Throne)
War of the Ancients 1: The Well of Eternity
War of the Ancients 2: The Demon Soul
War of the Ancients 3: The Sundering
Cycle of Hatred
(World of Warcraft)
Rise of the Horde
(WoW: The Burning Crusade)
Night of the Dragon
Arthas: Rise of the Lich King
(WoW: Wrath of the Lich King)
The Shattering: Prelude to Cataclysm
Thrall: Twilight of the Aspects
Jaina Proudmoore: Tides of War
(WoW: Mists of Pandaria)