The only thing I hate in WoD from tanks is when they don't keep Angra Mainyu facing a single direction, the need to keep alternating the floor AoE red/blue becomes very annoying when Angra Mainyu is spinning around all over the place and so have no idea where the red and blue is going to end up. When have three tanks new to the place it is pretty simple to say tank in the middle for AoE'ing the trash mobs if they all over the place so I have no problem with that. I am not a tank but I don't recall any other boss having anything uber tricky to tank in WoD from my perspective though I could be wrong. Casters and healers I imagine have the more tricky jobs in WoD.