I know there is an addon that you can get that gives you achievements for doing certain things on hardmode, ie. no arcane spells for mage or killing certain mobs. Would be really cool if blizzard incorporated these into the game with the upcoming new servers or hopefully down the road, either through an achievement tab, or some instance add it to your buff list, just something to consider. I just think that blizzard should look to incorporate more addons/weakauras into the base game more often as a whole in any version of the game