With all due respect, I really dislike these ideas.
It seems to me they are just being put there for the sake of the "rule of cool": if it's cool, they should add it! In my opinion, this is not good for the game.
-Arakkoa for the Alliance, really? This makes as much sense as making Hogger the king of Stormwind. Just no. Ogres should have been in the game since launch, though. They are a great addition to the Horde.
-Fire magic for DK's? Please. DK's deal with frost and unholy powers, not fire. This idea is as dumb as those suggestions to make a new spec for healing for DK's. Yuck.
In general, the ideas are weak, unoriginal or the dev's have already said they won't be adding them for diverse reasons. Just because some idea is cool does not mean it should be added, either because of lore, game mechanics, or because of developer time/resources.