Patch 6.0.2 (14-October-2014): Devouring Plague now always costs 3 Shadow Orbs, and now heals the Priest for 100% of all damage it deals, instead of healing per tick.
Patch 4.2.0 (28-Jun-2011): Devouring Plague damage done has been decreased by 12%.
Patch 3.3.0 (08-Dec-2009): Shadowform: This talent also now causes Devouring Plague and Vampiric Touch to benefit from haste. Both the period length and the duration of these spells will be reduced by haste. In addition, the mana cost has been reduced from 32% to 13% of base mana.
Patch 3.2.0 (04-Aug-2009): Cooldown removed but may only be inflicted upon a single target.
Patch 3.1.0 (14-Apr-2009): This spell now has a new icon.
Patch 3.0.3 (04-Nov-2008): The bonus coefficient has been increased to be on par with other DoT spells. Base damage on ranks 7,8,and 9 decreased to partially compensate for better scaling.
/Patch 3.0.2 (14-Oct-2008): Devouring Plague made available to all priests.
Patch 1.8.0 (10-Oct-2005): Will now properly consume the Inner Focus effect when cast.
Patch 1.6.0 (12-Jul-2005): Health leech effects no longer give you health while you are a ghost.