Guys, come on, look at what Vol'Jin has done in World of Warcraft!
He mourned his father.
He was tapping the keg during Brewfest.
He was standing in front of Undercity during the rebellion.
He was listening to Thrall, when he handed the leadership to Garrosh.
He got rid of another troll. Took him about 5 years.
He got removed from Orgrimmar.
He said to a Blood Elve that there may be trolls in a huge troll city.
Who other has such a list of achievements?
Seriously, I like Garrosh how he was during WotLK and Cata. He was angry, bloodthirsty, cold-blooded and active. He was everything that comes to mind when you say "Orc". Totallo opposite to Thrall, but much more, well, orcish.
Adding a "big bad guy" story around him and preparing to replace him is bad already, at least for me. But why Vol'Jin? He was around in the game for so many years, and despite being really liked and called awesome during early WoW, he did not do anything at all. He is boring, bland and all his actions seem meaningless. And he is a troll. Come on, maybe Tyrande should lead the Alliance?
Among the better choices:
Saurfang - although he is old, he is a war hero. Lorewise it would be a beloved leader for every race among the Horde - maybe without Forsaken, but they don't like anybody. Who wouldn't pick him?
Rexxar - shrouded by mystery since freaking long time, half-orc who was considered one of the most powerful creatures in WoW for some time. Agree, he is rather a loner, but it is not hard to make up a story about him sacrificing his lifestyle for the Horde.
Garona - after her reemengance during Cata I really hoped to see more of her. Cunning, wise and experianced, she could lead the Horde to the vicotry. She has a long "neutral" background, so if Blizzard wants to calm the war down it is not a bad option.