Anyhoo, here is the blurb I got from Amazon:
The D&D Encounters thing, makes this look like this is on the same sort of level as the Living Greyhawk Gazetteer was.Into the Unknown: The Dungeon Survival Handbook on Amazon wrote:Into the Unknown: The Dungeon Survival Handbook (Dungeons & Dragons) Hardcover – May 15, 2012
D&D ENCOUNTERS SUPPORT: This product supports the D&D Encounters in-store play program by providing Dungeons & Dragons players with exciting new options for their D&D Encounters characters. The player material in this book is also suitable for home game use.
CHARACTER THEMES: This book presents several new character themes tied to dungeon exploration. Themes are popular with Dungeons & Dragons players, as they provide more depth to each character's back story and provide intriguing in-game benefits.
This book also includes advice for Dungeon Masters on how to integrate character themes into an ongoing campaign that features dungeons and other subterranean environments, as well as dungeon-building tips.
This product has tangential ties to the drow-themed marketing campaign.

I don't know anything about D&D Encounters. Is this book set in Nentir Vale/Nerath? Do you need D&D Encounters adventures to get the best out of this book?