My fav race is an undead, and I have to force myself to play the others for variety sometimes cuz I stick to them so much, at first I was like "Whats with all the forsaken hate?" But then I quickly realized that they're right. Once Arthas is gone, what will happen then? Because the game plan appears to be kill everyone else.

While I would LOVE some crazy thing that would split the forsaken into some 3rd playable faction, I'm absolutely sure that Blizzard is just gonna keep it Horde and Alliance. While I wonder if they are just gonna lore break it and go into the next Expansion without mentioning why she's going on, I doubt it as they've gotten real good at quests and explanations. But somehow someway the undead will stay and continue through cataclysm. Either that or half of them will split off into their own faction.

Something intriguing about the forsaken is that they are one of the only races that their numbers will not increase. As far as I know, the forsaken are not raising undead back, so once an undead dies, their numbers decrease by one. After 9 years since War3 TFT you gotta think their numbers are dwindling lol.