If I could have one wish about a change to tanking in Cataclysm it would be to require at least 3 tanks for every encounter. But, as you'll know if you read my posts, I'm just a bit too nostalgic for the days of 5 tanks per raid in Vanilla WoW.
I personally am a fan of tanks having at least three abilities to help them mitigate damage. Currently most tanks have a 'shield wall' type ability that is a flat percentage damage reduction. This is their button that they hit when they fear for their life.
Another is the 'last stand' type mechanic that increases the maximum life of the tank for situations where shield wall is unavailable or their damage incoming is horrendously high. This ability is less relevant as of late since Blizzard has been moving away from the spiky RNG style tanking that was popular in Ulduar (hardmode Thorim and Algalon, for example).
The third is a less powerful mitigation style ability like Ardent Defender, or Shield Block. I'm a big fan of how they have designed Protection Warriors. They provide a ton of utility, some of which is unique (improved Commanding Shout). They bring sunders, Shattering Throw, and have four seperate defensive cooldowns when their T10 4-piece is factored in.
While having all these abilities, Warriors are still not an easy mode class. I'm not a big fan of the Ardent Defender move. It is a mini shield wall that is activated if a Paladin's life drops too low. There's not alot of thinking involved there. When raid healing it's amazing the difference between healing a Paladin and a Warrior even though they bring comparable utility on paper. Healing a Paladin is like being on cruise control until AD goes off at which point you're like 'oh crap!' and have to actually start paying attention.
I think the Warrior, with multiple tanking cooldowns as well as a wide variety of stuns, snares, and other defensive abilities is the way to go with all the tanking classes in Cataclysm.
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