Ideally, tanks would be receiving a relatively constant stream of damage over time. The high levels of tank avoidance players have obtained is making the incoming damage a tank DOES take more 'spiky' than is healthy for raiding. So if a raid's main tank had 30% dodge normally, in Icecrown Citadel they will effectively have 10%.
The spell, called Chill of the Throne, will allow creatures to ignore 20% of the dodge chance of their melee targets. For Icecrown Citadel, we are implementing a spell that will affect every enemy creature in the raid.
