Tanks do not equal DPS. If your pulling more than 3K to 5K DPS, your probably not a tank, your tanky.
So, do you want to be Tank or a Tanky?
And, other than some changes to Block Cost, not much is happening with Tanks in the upcoming content that is not happening to everyone.
My Tank is an Imperial DK, but I play him more of a hybrid. That is not saying much as I recently changed some things about his build and I am still trying to figure it out. You have to remember that with a Tank, Health is your biggest Resource to worry about, then Physical Resistance, then Magic Resistance, then Block Cost Reduction, then Healing Received, then finally Stamina and Magic, and only to the end that you can apply your Taunt and Group Support skills as needed during the fight and Block when you need to. It's a whole different mindset than playing a Stamina DK DPS.