Gamasutra has an interesting article exploring the creation of the World of Warcraft line of gaming books released by White Wolf's Swords and Sorcery imprint. Written by Luke Johnson, the co-developer of the line from White Wolf's end, it has a lot of good detail for fans of tabletop (or pen and paper, as my circle of geekish souls always called it) roleplaying games as to the challenges and difficulties of converting a sprawling property like WoW from the rigidly controlled computer game to the much more expansive format of live gaming.
I own pretty much every book White Wolf's put out (both in terms of their WoW property and in general, I buy a lot of gaming books) and I have to say I found Luke's points about how the relationship between White Wolf and Blizzard as far as developing the lore in these books to be absolutely fascinating. Blizzard clearly wants to keep the development of the property and its lore firmly in their control, which on the one hand is totally understandable and yet on the other hand really shackles the writers hired to work on these books. You can't just throw in that Orcs like to eat human babies - any cultural note, even an offhand reference to humans having a lot of festivals throughout the year or trolls not liking large groups, needs to be accepted or rejected by the folks at Blizzard, which can really slow down the production of the books. The upside to this kind of supervision is that the RPG line can be used as a sourcebook for troubling lore questions for nerds like me. The downside is that it takes much, much longer to release the books if they have to go back and forth to Blizzard and wait for the team there to have time away from making the MMO in the first place to check what you wrote and decide if they want Harpies to be offended by flutes. The tightrope they walked between providing content and satisfying the folks at Blizzard is a problem I'd not considered in adapting something like this.