I think you are missing the point of the change. The idea is so that in the future they will move the tanking model to more like the DK active mitigation style, where the tanks skill will determine how much or how little damage they take.
Try healing some DKs that don't know how/when to DS and you will get the idea. Bad tanks will require more healing once this change has been finished, read the watercooler blog to see where it is heading.