James Gurney is an illustration and anthropology graduate. In his career as a freelance illustrator he reached fame through his Dinotopia book series, featured in the New York Times Best Selling List. He's also drawn for the National Geographic Magazine.
James Gurney visited Blizzard Entertainment back in Oct 2009 to train senior concept artists.
His relationship with Blizzard has grown over the years, and when Chris Metzen pitched the idea to create Diablo III: Book of Cain, James Gurney was among the exclusive artists to be commissioned for the illustrations of Diablo III: Book of Cain.
Eroldren sent my way a heads up that James Gurney posted in his blog a short unofficial video of the making of his commissioned artwork for the Creation of Sanctuary section (page 60). It is the Pandemonium Fortress, built originally to house the Worldstone during the Eternal Conflict.