Okay I remember some time in cata Blizzard was talking about making female demon pets(just different skins) for the warlock pets. Now I have not heard anything about it. Did they say that they were going to scrap it?
Here is some info that I have found. http://wow.joystiq.com/2011/04/14/wa...of-all-demons/ (cough, I would not hold your breath for 5.1 either ^.^)