The more I raid, the more I prefer Rejuvination to Regrowth to spending my extra mana and time not devoted to keeping a LB and a RJ up on the tank(s). I do still use Wild Growth, as well, when the Melee around the tank take an AoE or are generally all losing a bit of health - but is 'Revitalize' going to help Melee DPS and the tank that much? I cannot possibly come up with some crazy function that would tell me average potential DPS/point of rage,energy,runic power - but I do know that during an entire 10 Naxx i gained a whopping total of around 3,000 mana. I would have never missed it in the slightest, and all of the other casters received about the same amount. Because of the dull performance of 'Revitalize' and my waning use of Regrowth, I tried out the Celestial Focus build, taking one point out of my "Oh shi-!" macro intensifier Empowered Touch and I feel that it does a really good job at letting me spread my HoTs out more quickly and letting me use Nourish to greater benefit with my 4-set of t7.

It's a combination of both. The huge health pool balances all the extra incoming damage VW will take. Yes, I know the 80% AE reduction is the clinching point, but if he had HP comparable to regular tanks, it would be real fun to heal him.

Yes, the VW is really nice to tank sarth3d if the warlock keeps it out of incoming flame waves.
Having the VW turn the wrong direction will cause sarth to breathe on the raid, causing an instant wipe. This is so annoying I think it balances out.

It appears that Innervate is not getting changed in terms of it's coefficient. However, it also appears that the overall nerf to mp5 out of the 5 second rule will not be nearly as bad as some people have been predicting.

In all honesty, I don't see this really changing any resto itemization for the most part(past the DMC: Blue Dragon becoming a much less desirable trinket).

Source: MMO-Champion BlueTracker - I don't get the regen nerfs...

If you're refering to the crit rate added by agility as "block", that's a hard sell to make. A strength gem will consistently provide an extra ~8 damage absorbed, while an agility gem will only increase the chance of proc'ing a shield by ~0.2%. To me, it seem's like the age old discussion of dodge vs. hp. One is reliable survivability and the other isn't (i'm obviously in the HP camp).

I wouldn't be surprised if str/stam overtakes agi/stam as the "best" gem when you dont consider color/set bonuses.

He said it boosts it higher. The armor and dodge that agility provides already makes it the best avoidance stat. The added dodge and armor alone will make the shield stronger (higher dodge -> less chance boss takes down the old shield, more armor -> more dmg reduced). On top of that, agility also boosts crit rate. That's just an added perk. 8 damage is nothing when patchwerk-25 hits you for avg 16k. Even a 0.05% added dodge rate would be better if the shield had a 100% uptime.

However, STR gems might replace expertise gems for threat (since the block might be better than avoiding parry-haste).

It's not. Avoiding parry-haste is better than block. Also expertise increase your chance to hit and then your crit (for 2-roll system) and consequently shield up-time.

Atm only faerlina and Patch don't have parry-haste and I don't remember bosses where magical mitigation overcame phisical one (if you suppose to do Saph with FR and KT with interrupts). For istance every time I don't tank Maly and one of our tank dies is because he have taken 2 parryhasted attack, the same holds true for sarth.
As for Ulduar I expect it will be far more focused on tank-phisical damage than magical damage than now, simply because otherwise druids and dks will have too much easier life than paladins and warriors, and I think it's something Blizzard wants to avoid.

Edit: Expertise is also a far better threat stats than Str.

Edit2: Yes, we will see a day when we will gem for Str our tanking kit. Actually I'm expertise hard capped and I have 54% avoidance in a raid environment, so yes probably when we will be expertise capped and we will have around 60-65% avoidance, str will start to be a better stats, but only because we will have enough agi/dodge and expertise per se.

Erm, how do you infer that encounters will be mainly physical from a mistaken impression that magical damage benefits Druids/DKs more than Warrior/Paladins? Where do Druids get this awesome magical damage tanking ability from? Massive stamina? You're not making sense.

You may as well say that Ulduar bosses will be mainly physical damage simply because it'll be full of golems and giants, at least that might be more accurate.

For DKs I don't think I need to explain.
For Druids, we have more stamina (and we know how much it's important, look at Sarth 3D tanking for example). But we also have more magical mitigation due to:

Savage defender
Barkskin (shield block works only on phisical damage)
Protector of the Pack (12% magical mitigation, warriors have 6%, paladins have none).

A druid takes 20%*12/60 = 4% less magical damage on average due to barkskin + 6% less damage than a warrior from PoP = 10% less magical damage than a warrior and 16% less magical damage than a paladin without counting the new savage defender. Also the magical burst are easyier to heal due to more HP (6-7K more than a similar level warrrior usually).

Warriors DO have defensive stance, which is a flat 10% damage reduction. On top of that comes imp. defensive stance, which makes it 16% (or rather, 1.1*1.06 = 1.166 = 16.6%).

E: beaten.