This is a very simple file mod that restores the Warlock talent "Sacrificial Pact" to its original Beta icon, before Blizzard panicked and sanitized it to avoid scarring the souls of vulnerable children and the elderly.
What self-respecting warlock wouldn't want to do that? Exactly. Now you can enjoy your Sacrificial Pact in its full and proper iconic glory, with the added bonus of damning to hell anyone who dares to gaze upon your user interface. In other words: win/win!
TO REPLACE THE ICON:
Unzip the "Icons" folder contained in this file into your World of Wacraft installation's \Interface\ folder, the same place your \AddOns\ directory is.
DO NOT actually put it inside the AddOns folder. It should coexist in peaceful harmony next to AddOns, inside Interface.
IF YOU ALREADY HAVE AN "ICONS" FOLDER:
For example, if you're using other custom icons.
Open the zip file
Open the "Icon" folder inside the zip file (you will see a single, lonely .blp file)
Unzip the .blp file itself directly into your preexisting Icons folder
IF YOU DECIDE YOU WANT TO GO TO HEAVEN AFTER ALL:
To remove the icon and return to the Blizzard default...
Go back to your World of Warcraft installation's \Interface\Icons\ folder
The game will automatically go back to using the official, squeaky-clean wholesome version.
Being serious for a moment (awww):
This page has my tongue firmly in my cheek — I'm being heavily satirical, playing on stereotyping to try to show how ludicrous it is to be upset about the original icon. But I also want to be fair, so I'd like to present a perspective Blizzard shared some time ago on this sort of change (available at Diablo IncGamers):
A lot of what we do now and have been doing for the past… 8 or so years, around the Warcraft III and initial World of Warcraft development era, is putting a lot of effort into crafting unique worlds. Meaning that we put more effort into every aspect of the game world itself. Who is this secret organization? What is their history? What’s their look? Do they have a specific accent? Do they have a symbol or mark that can identify them?
In the previous games I think there was a sense of “Oh it’s a demon, Diablo, devil, Satan, satanism… pentagram!” and while certainly there are those influences, what we’re creating now and have been creating for quite some time is evolving the game world and making something more complete. A complete world where every aspect is fully realized, maybe even if it doesn’t show up in the game.
I think that same sort of world-crafting can be seen between Warcraft II and Warcraft III. A big shift in focus to fleshing out a unique fantasy world and story.