Insight Editions has officially straightened up any rumors and confusion about conflicting release dates on different websites. Insight Edition has stated the Diablo III: Book of Cain will ship on December 12.
There you have it folks. Set your inner crave countdown. Fire up and start pre-ordering.
To find out more details about Book of Cain, we have posted an 8-pages preview, and more importantly our BlizzCon 2011: Diablo III Panel Transcript -- where Chris Metzen, Kevin Martens and Leonard Boyarski detail the lore of Diablo III, Diablo III: Book of Cain and The Sin War trilogy.
Source: Insight Editions Facebook Page