Ghostcrawler posted a new Dev Watercooler which focused a lot on Bloody Tanks and what they are envisioning for us. If you haven't read it yet, I would definitely suggest you read it.
Ghostcrawler listed three methods of active mitigation, which could be used to push Prot and Feral tanks more towards playing like Bloody Tanks. However at this point in time there is no clear path, and they may even decide to choose a fourth completely different path, or design each class with a model of their own. So I will let you draw your own conclusions for now and not comment until more information becomes available.
What is interesting though is the impending changes that Ghostcrawler announced for us in patch 4.3, which make me wish they would hotfix it in, or hurry up and do patch 4.3 already, even though I'm still not finished with the current content.
The first change Ghostcrawler promises us is a reduced cooldown of 30 seconds on Outbreak. This will put both our diseases on the target for 21 seconds. Leaving us with only 9 seconds of down time on the diseases without having to spend Runes. The ultimate effect of which will be that we will no longer use Icy Touch and Plague Strike, allowing us an extra two or three Death Strikes every minute. I can't really complain about more healing and shielding while keeping our debuffs up. The only issue is that Outbreak can still miss if you're not hit-capped (which you should not be), and with a 30 second cooldown, it leaves you vulnerable for 9 seconds. What Ghostcrawler may be implying is that as Bloody Tanks we should be spending our talent points on Epidemic, and forgo getting Lichborne as a cooldown.
Next Ghostcrawler makes a vague promise to do something with Blade Barrier in patch 4.3. Currently we need to babysit our runes and use Rune Tap or Heart Strike whenever one of our Blood Runes is off cooldown to keep the Blade Barrier up. At the same time being careful not to spend a Death Rune on them, as those are better used for Death Strikes. From the wording it sounds like they will make Blade Barrier something that will always be on, or possibly something along the lines of it being up for 20 seconds after you use Death Strike. This is all speculation at the moment, but if they do it right, we may need to do less babysitting of our Runes.
Currently Death Strike can miss. This is an issue, but one we are forced to work around as stacking for Hit and Expertise is not realistic and would cost us too much in Mastery and avoidance stats. Ghostcrawler is suggesting that even if our Death Strike misses, we still get the healing and shield. He does note that this is likely an interim change until they can do a major overhaul of all the tanking specs and align their mitigation towards the Bloody way of life. But hallelujah, if this becomes a reality, even for the duration of patch 4.3 to the next expansion, it would make our healing and mitigation a lot more predictable.
Ghostcrawler also talks about our Bone Shield, and suggests ideas they may implement to make it more useful. At the moment, Bone Shield is only good for 8 seconds (the first 4 hits with 2 second intervals), however Ghostcrawler suggests it may be better used as a spike mitigation and only use up a charge whenever a large hit occurs (say a hit that takes away more than 40% of your total health). Prot tanks have additional mitigation through Block, which prevents large damage spikes, for which Bloody Tanks have no equivalent. We get hit more, and we take more damage. A good tank can recover from that quickly with a Death Strike or two and some help from the healer, but it could swiftly kill a beginning tank. I am assuming the "20% less damage while at least 1 charge remains" would change into a reduction of a single big hit which will consume a charge. But we shall see, dreaming about an "always on" 20% damage reduction is nice.
Lastly Ghostcrawler talks about Blood Shield. He cautions this as being a long term change, and provides very little information on what they actually plan on doing with it. They like the fact that we can heal ourselves and give ourselves a nice large damage shield after getting hurt a lot. But if you used your Death Strike right before a damage spike, or you miss (not so much an issue if the previous "always heals & shields" change goes live), you lose out on a lot of mitigation. Time will tell how they plan on tackling this, and I am looking forward to their design ideas on this model. I love getting Blood Shields for 100K or more, but getting them is rare, and very hard to do.
So far I am looking forward to patch 4.3 and what it will do for our tanking. Time will tell what will happen, but always remember Ghostcrawler promised us a pony.