So according to blizz, 8 new rares are added.
We already know how two of eight will look like.
I searched for deth'ilac in wowhead's ptr database, and found what's apparently his brother(sister?) or something like that, called Beth'ilac.
My guess is their skin will be the same, possibly recolored abit.
Here's a link, press view in 3d to see the model.
http://ptr.wowhead.com/npc=52675#.