Technical Game Designer Chadd Nervig, aka Celestalon, has been answering some inquiries on Twitter lately, and hinted at a few of the changes we can look forward to with tanking. It seems all tanks are up for tweaks, in some fairly overarching ways.
.@abcart311 All tanks. Current plans: Tweak the design of Resolve. Lower tank health. Lower tank mitigation. Lower boss damage.- Celestalon (@Celestalon) August 29, 2014
If you're not familiar with Resolve, it's essentially what Vengeance has become in Warlords of Draenor, albeit with some changes. Currently, Resolve improves self-healing and absorbs done by the tank to the tank and partially converts mastery to attack power. How it will be further tweaked in Warlords remains to be seen, but the overall change itself should help tanks be tanks without overshadowing the DPS.
The rest of the tweet is much more intriguing, but does fit with the overall theme of scaling down we're seeing in Warlords. Lowering tank health and mitigation seems risky, but if boss damage is also reduced, then it shouldn't be a problem. For a long time, Blizzard has made noises about how they wanted to slow down the pace of boss fights, especially in the final tiers of an expansion. Damage that's less devastating, healing that is slower pace and choices that are more meaningful. To me, these changes read as being in line with that philosophy. I will be interested to see them implemented, and how they affect gameplay in the beta.