Published by Insight Editions and titled The Cinematic Art of Wrath of the Lich King, it features 200 pieces of high-res concept art and CG renders, two 8x10 art cards with concept art of Arthas and Sindragosa the Frost Queen, lots of lore bits about major players in Wrath's storyline, and (I think this is the coolest) a 12-page illustrated storybook that tells the tale of Sindragosa. And even beyond all that, there's behind-the-scenes commentary about the cinematic every step of the way. It's valuable insight if you're interested in storyboarding, production, or just the Blizzard creative process.
I think we can all agree that it sounds pretty awesome, whether you're into art or WoW itself. You can pick it up, if you're so inclined, at Amazon.com for the very reasonable sale price of $19.77 USD. If you're as-yet-unconvinced, you can check out a preview of the book at Blizzard's Wrath site.