Well, since they have admitted that the hybrid tax no longer applies, I can see only one fast way to save the expansion without hotfixes backpedaling.
Remove completely all the healing arsenal from Rets( maybe keep WOG) and buf directly the dps abilities. This will recreate the profile of the spec as a holy warrior. A melee twohander with holy damage attacks in their disposal. This way you touch the DK idea of a warrior with spell dps abilities but distinguished enough as a twohander only and in holy department.