Tanking in cataclysm means that you should be doing a lot more threat than DPS in the same gear as you. Vengeance is a powerful weapon and as long as we have that it'll be hard for DPS to pull off of us. Thrash is your main AoE move don't worry about AoE threat right now. I'd say paladin tanks have the easiest time tanking while raid leading, but I feel once we get use to our rotation then we'll have it just as easy.