Patch 5.0.4 (28 August 2012): Updated; changed from Grants you an additional X% haste while in Unholy Presence. In addition, while in Blood Presence or Frost Presence, you retain Y% increased movement speed from Unholy Presence.
/Patch 4.0.1 (12-Oct-2010): No longer causes Runes to finished their cooldowns quicker. Now grants additional haste while in Unholy Presence