Blizzard has a long history of taking popular addons and rolling their functionality into the game's base user interface. The first instance of this that I can remember was when Blizzard introduced its own quest objective tracking overlay, nearly copying MonkeyQuest's original configuration. The dev team also inserted dungeon maps for the various instances, taking a page out of Atlas' book. Their latest invention is a replacement for Power Auras, the popular notification mod that displays custom graphics when a specified event occurs.
Looking at the list of spells for which Blizzard created custom "spell activation" effects (thanks BB!), we see mostly random and reactive abilities on the list. Paladins will enjoy the art for Art of War, and every mage spec has a particular proc to watch patiently for. What intrigued me was that there is actually a spell activation effect for rogues, an orange lightning bolt that represents Slice and Dice. Slice and Dice, as any rogue will inform you, is not a random proc; it's a core part of our DPS and should be up at all times. While having a lightning bolt on my screen at all times sounds like fun, it got me thinking about the rogue DPS model. I utilize Power Auras extensively on every other character I play, yet I don't even have it enabled on my rogue.