We want to move the shorter cooldowns like Shield Block, Holy Shield and Savage Defense so that they work more like Death Strike. Blood DKs have a lot of control over the survivability they get from Death Strike, but as part of that gameplay, they have to actually hit their target. The other three tanks will get similar active defense mechanics. This doesn’t mean everyone needs to use the DK model of self-healing, but they can use the DK model of managing resources to maximize survivability.
We toyed at one point with the paladin Holy Shield being a Holy Power consumer and we think we could do so again. Heck we could make Word of Glory the thing you’re supposed to do with Holy Power, so long as we balanced all tanks around that idea and didn’t feel it infringed too much on the DK mechanic. We could make Shield Block cost rage, and change Protection warrior rage income such that they had to manage rage, the way Fury and Arms warriors now must do. If tanks generated more rage from doing damage and less from taking damage, then hitting a target becomes very important, but for mitigation, not threat management reasons. This is a bigger change than it seems though. We don’t want a model where the Prot warrior ignores Shield Slam, Devastate and Revenge (since threat isn’t a big deal) in order to bank all rage for Shield Block (because survival is). Imagine a rage model where you always had enough rage for your core rotational abilities (they could be cheap or even generate rage), so that you could funnel most of your rage into Shield Block when survival mattered and Heroic Strike when it did not. Redesigning Savage Defense to make it a rage sink is an even bigger change, but we think there is an opportunity there to make the rotation more interesting for druids (and all tanks really). Their rotation would help them achieve the goal that usually matters the most to tanks: living.