Yes you can with Divine Guardian.

The problem with tranq is there are very few fights where there is enough heavy raid damage to warrant using it more than once. Typically there will be that hard phase where you'll definitely want to be using it, but those phases aren't long enough to where a 3 min CD is going to be used twice in any beneficial matter. So the reduce CD of tranq. is most likely just going to result in meter padding.

Druids are probably only hurting on raid spots when you get into heroic encounters where you may only be bringing 5 healers. Cho'gall and Sinestra for example. Would you bring 2 priest, 2 paladins? Yes. Would you bring 2 druids? Probably not. Would a 3 minute tranq cause a raid leader to utilize 2 druids? Probably not. Well Cho'gall's shadow aoe attack does goes out every 45 seconds, so 2 resto druids could cover every single one of them when the Adherrants spawn (which happens every 90 seconds after 85%). But if you use a mage/pyro strat on Heroic Cho'gall barriers/sac/AM/DG are much more beneficial since the mages aren't healable.

I don't know what you are talking about in 25 player heroic modes:
Halfus - one near the start, one near the end.
V+T - healing after blackout in each P1.
Cho'gall - once after a shadow aoe and once in the last phase.
Conclave - 1st and 3rd (and potentially 2nd/4th) frost aoe.
Al'akir - potentially one use in P1 and one at the end of P2 as per norm.
Magmaw - 1-2x in P1 and 1x in P3
Tron - during the fire aoe you can get at least 2 uses off.
Maloriak - both red phases or just one in the red and one in the final.
Artem - after the fire AoE blasts (I never see the need until near the end personally)
Chimaeron - fued and pre-P2 transition.
Nef - P2 and P3.

So that is essentially every heroic encounter in this tier of content (sans Ascendant Council) where you can reasonably pull off 2 Tranquilities and some you can pull off 3.

[e] Amended the fact I am talking about 25 man*

Well I'm glad that there are uses for a 3-minute Tranquility in heroics! Is this with respect to a 10-man or 25-man fight? Or would you say it's applicable for both?

Oh I wasn't trying to imply that it is better than traditional cooldowns or even worthy of saying "right we need two Druids to cycle Tranquilities for x". I would say the times I listed can be counted as "good times to use them" where the effect is useful to the raid and while the majority of the time a DR cooldown is better there are times where I would say Tranquility could almost be reasonably comparable. These being Magmaw, Magmatron, Chimaeron, Halfus, Cho'gall and Nazir mostly - you can see the key trend here being when damage is spread out over a short duration rather than a huge burst.

I left out A'Council as the post I was responding to said there were few or no times where 2x Tranquility was useful and I only set out to show that there are plenty of times to meet that criteria outside of the current "oh shit panic" button it is now and in more of a choreographed setting. I have no experience with Sinestra to be able to feel comfortable saying times of use and again you only listed one time rather than the stated 'more than once' post.

As to Sasazuka I personally couldn't comment on the balance issues of 10 man although I would say the same should apply fairly well provided you are not required to have all 3 of your healer spots used for DR cooldowns in order to meet a rotation setup. If anything it should have slightly more effect in 10 man as it obviously brings the raid up a lot faster and the DR cooldowns provide less 'healing' in comparison.

Yeah, I wasn't sure which you were trying to do. If we do want to point out places where Tranq is actually really good, I think some of those are stretches (Magmatron, Halfus). I think the places in current content where Tranq really "matters" are:
--Chimaeron P2 transition. You want to top off the raid basically instantly after a Massacre and then transition. We use all our Tranqs simultaneously here and it helps set up a clean P2.
--Council and Cho'gall burn phases. Steady raidwide damage over a long period, and clumping up is impossible (at Council at least--at Cho'gall PWB is ineffective in P2 for a more subtle reason).

Then there are times were Tranq can be roughly as good as a barrier. As you described, the main issue is whether the raid damage is spread out over time. The thing is, Tranq takes ~6 seconds to channel and even longer to deliver the healing from the HoT (which is a large chunk of the healing). Very few boss AE's take more than 3-4 seconds to deliver their damage. The big ones are Nezir's Sleet Storm and (kind of) Feud. But what other ones are there? Magmaw's AE is 4 seconds and he casts it so often you can't Tranq them anyway. Halfus stuns so you can't even cast Tranq during it (but you can have a PWB down--incidentally, PWB on the tanks during Furious Roar was a critical part of the strategy on our early kills). Cho'gall's Shadow is close maybe--6 seconds IIRC.

This is a good summary of the whole situation really. A few fights Tranq is good enough to feel like a "real" cooldown. One situation where it truly uniquely stands out (and on that one, Chimaeron transition, Moonkin can give you 1-2 anyway). Zero fights where I, if I were a raid leader, would feel compelled to start bringing more Druids than I currently do because of Tranquility cooldown reduction.

Hamlet and co, can I just safely assume the discussion on tranquility and its worthiness to be called a CD is centered around heroic raids? Personally I have not done any heroic raids, but in normal raids, I don't find myself lacking a CD or lagging behind my fellow heal mates (in 10m). Yesterday night we downed Chogall (normal) 2 healing it with me (resto drood) and a holy priest, I popped TOL at the beginning of P2 and timed tranquility towards the tail end of TOL, and I I felt I made a difference (of course my leet holy priest mate also played his part).

Thanks for clarifying. I thought I'd ask because it is not clear. For those of us who are not in heroic raids, don't be unduly concerned as normal raids, we do just fine! *Resto4Life*

I get that we're throughput healers with movement utility rather than damage mitigation healers. I like the variety. To that end, allowing tranq to channel while we move would give us a niche, and raid leaders would value that utility on progression. It is a real limitation on the more challenging content that we can't use our most powerful CD without stopping everything else for six seconds. I barkskin whether i need it or not, just b/c.

"Druids now innately have 100% pushback protection from damage while channeling Tranquility."

This removes everyones concerns of having to waste barkskin on the new 3 minute Tranquility I guess. Pretty nice change.

Where did you see this? I can't find it in the PTR patch notes.