0600Patch 6.2.0 (23-Jun-2015): Shadowform no longer applies its visual effect to the Priest's mount.
0600Patch 6.0.2 (14-October-2014): Shadowform no longer allows any healing spells to be cast but also no longer has a restriction on casting other Holy spells.
0500Patch 5.4.0 (10-Sep-2013) Shadowform now increases the Priest's armor by 60%, but no longer reduces all damage taken by 15%.
0500Patch 5.2.0 (5-Mar-2013): Shadowform now increases the Priest's Shadow damage by 25% (was 20%).
0300/0400Patch 4.0.1 (12-Oct-2010): [Cure Disease] can no longer be cast in shadowform.
0300Patch 3.3.0 (08-Dec-2009): 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.
0300Patch 3.1.0 (14-Apr-2009): Now reduces all damage taken by 15%, not just physical damage. Bonus damage from critical strike chance removed and replaced by the ability of those periodic damage spells to generate critical strikes.
0300Patch 3.0.8 (2009-01-20): You can now shift into Shadowform while mounted or sitting.
0300Patch 3.0.3 (04-Nov-2008): Shadowform: Devouring Plague, Shadow Word:Pain, and Vampiric Touch cast in Shadowform deal increased damage percentage equal to the player’s chance to get a spell crit on their target.
0200/0300Patch 3.0.2 (14-Oct-2008): Now has an innate 30% threat reduction. Now has a shapeshift UI.
0200Patch 2.4.0 (25-Mar-2008): Fear Ward is now usable while in Shadow form.
0200Patch 2.3.0 (13-Nov-2007): Fixed a bug where the global cooldown was triggered when shifting out of Shadowform.; If you are in Shadowform and try to use an ability that my not be used in Shadowform, you will leave Shadowform and use that ability. This can be disabled with /console autoUnshift 0
0200Patch 2.0.3 (09-Jan-2007): The visual effect of "Shadowform" will no longer persist if disabled while mounted.
0100Patch 1.7.0 (13-Sep-2005): Switching to Shadowform no longer cancels Holy buffs on a priest.
0100Patch 1.6.0 (12-Jul-2005): Changed so all spells except Holy can be cast rather than only Shadow and Discipline spells. Tooltip updated. This fixes several bugs that prevented various actions (creating tradeskill items, mining, summoning a mount, using a hearthstone and many more).
23 June 2015 +, 14 October 2014 +, 10 September 2013 +, 5 March 2013 +, 12 October 2010 +, 8 December 2009 +, 14 April 2009 +, 20 January 2009 +, 4 November 2008 +, 14 October 2008 +, 25 March 2008 +, 13 November 2007 +, 22 May 2007 +, 9 January 2007 +, 13 September 2005 +, 12 July 2005 + and 7 March 2005 +