I think I'm going to take Sylvannas out of my Control Warrior list. Against Shaman I almost never play it because it just gets hexxed and I spend 6 mana doing nothing. In the mirror match you almost never play it because of Acolyte of Pain. And against decks like Secret Hunter it's just too slow. I think the only matchup where Sylvannas is good to have is against Reno Lock and those are pretty scarce on ladder.
Not sure what I want to add currently. Maybe a Ragnaros but probably not. Maybe even like Deathwing or something. I know Soggoth is showing up in Control Warrior lists so I might try him first.