Feel free to remove- no longer relevant in new patch.

I took a look at your list and noticed some drawbacks in your mastery gearset. [Wyrmbreaker's Amulet] > [Lightning Flash Pendant]. Or are you saying that mastery is better than spirit? And again how can [Mandala of Stirring Patterns] be better than [Tyrande's Favorite Doll]? With [Heartbound Tome] and [Scepter of Ice] the difference is 13 mastery and 7 spirit. Which is realy better? Can you tell me your reasoning with all these item choices?

Strength of Soul is an easy talent drop. You'll find yourself casting heal less and less in raiding environments as your gear grows to be able to handle Greater Heals in between your shields, PoM, Penance and PoH. Heal is great for filler when there is very little damage going around and you'd like to keep up some HPS into the tank or try to keep inspiration rolling, but the reduced cooldown on weakened soul just isn't that good.

PWS will be your most mana-efficient Single Target Heal. You'll not only keep it on CD on the tank, you'll most likely be using GH or FH to reduce the Weakened Soul debuff in Order to apply PWS more often.

With the Patch SoS will reduce the Weakened Soul Debuff with FH and GH, too. Since GH also decreases the CD of IF (with ToT) I assume GH could outperform Heal HpS- and HpM-wise, if IF is used on CD. Did anybody do some theorycrafting on that?

Unless I missed something, SoS only reduces Weakened Soul, not Rapture's ICD, but given the buff to PW:S's absorption amount, it's possible that the shield won't actually be absorbed until Rapture's ICD is over. Personally, I wouldn't risk missing it just to get another shield up, especially given the increased mana cost.

The other thing with SoS that makes me wonder a bit is that it directly conflicts with Renewed Hope; less uptime on WS means less uptime of +10% crit, and with the risks you're already taking by shielding before the Rapture ICD is up, it seems unlikely that SoS Shield spam on a tank will be optimal. SoS definitely seems like more of a PvP talent, where shielding someone more often means a better chance of them surviving, even if you miss out on a Rapture proc here and there.

EDIT: Never mind, I forgot that +10% crit from Renewed Hope also applies to targets with Grace.

The problem I see with SoS is it's conflict with rapture. Without a mod to track rapture's ICD you could end up stepping on it's toes:

Currently, you cast PW:S, it has up to 3 seconds to break (pretty reliable on a tank),
15 seconds later you can cast a new one with a pretty safe bet rapture is off cooldown for when it breaks (which could be instantly).
Using SoS without a rapture ICD tracker could result in you shielding the target once every 12 seconds, which would result in roughly 50% of your shields not giving rapture due to the irregularity between the shield breaking. The resultant effective time between rapture procs is 24 seconds. This is a horrible reduction in mana returns from rapture.

Effectively, if the only person you're shielding is the tank then you either sacrifice mana returns from Rapture by shielding as frequently as possible with SoS, or run a Rapture ICD mod and shield the tank 12 seconds after each shield breaks, which will probably work out close to 14-15 seconds between shields anyway. Alternatively, you could start blanket shielding in fights where damage is liberally spread out (nef P2, for example), your mana will drain fast but you'll get the most out of Rapture.

Actually PW:S is going to be the best HpM and HpS heal we will have with the changes. So we won't just use it for "free raptures" every now and then. In Phases like the Nefarian 2 Phase PWS should really shine, since it's not going produce a high overheal plus you don't have the PoH problem, not having 5 man groups in range and losing further efficiency due to overwriting the Glyph heal.

I tried some rough number crunching on the new Renew, especially since we will most likely be running with IW up, when assigned to raid heal. Glyphed and skilled it should land in the 8 HpM area when reaching the haste softcap for Renew6.

I've also found shield spamming to be very effective at healing some heroic fights, like Maloriak. And of course the sub-20% phase for Chimeron, shield spam is the only healing anyone can do. Most fights I find that there's some section of the fight where you want to cast 2 to 5 shields in a row, then go back to your normal healing routine. So I've been pretty happy with all the shield enhancement talents. I'm actually considered building a gear set specifically for shield fights that focuses on spirit + mastery (in contrast to spirit + crit for regular healing or spirit + haste for smite).

You are right, tick-based spells which scale with haste get rounded up if they are hasted above a value of x.5 total ticks. In addition, the overall ticking time will get adjusted, so not many Renews are actually running exactly 12 seconds.
This rule also applies to our Hymns, I did plenty of testing about this on the PTR.

I dont know why 13 pages of maximizing disc discussion theres never been the discussion of replacing spirit for every other stat.

In 80% epic gear with Evangelism, Tide, Rapture, Blood elf racial,. Reforging ALL spirit to haste>crit>mastery going all out Throughput Ive still been swimming neck deep in mana to the point I dont have to hymm or fiend on any encounter unless the raid calls for it.

Even being aggressive with poh, mana is still so abundent because Tide, Evangelism that Ive been considering grabbing mage/warlock gear with 0 spirit just for throughput because I feel sitting at 50-60+ percent mana for a majority of fights is a waste.

You are running normal modes with 7 healers - I'm not surprised you have an excess of mana. Go ahead and get that mage/warlock gear, and spec shadow.