Gamasutra has a 3-pages interview with Luke Johnson, World of Warcraft RPG Developer from White Wolf Publishing.  In this interview titled:  Translating World of Warcraft into a Tabletop Roleplaying Game: The Content Challenge—Luke goes into the process and challenges of creating the WoW RPG line.  Each RPG book contains more words than a novel, and comes packed with info based in the Warcraft setting. Some of this info comes from Blizzard Developers who share details of upcoming expansions, getting published on the RPG book prior to the release of the expansion. That was the case with Wow RPG: Lands of Mystery which covers never seen material and details Northrend and the South Seas.

Luke Johnson talks about WoW RPG: Dark Factions, which he reveals has been in development since 2005 and the setbacks that have kept the book from getting published.