Obviously, different things will work for different guilds. If your guild has a Prot Paladin kiting slimes who also wants to Cleanse, that portion of the post isn't very relevant to you. Having a healer's perspective is nice because we can make the call on removing the MS in order to save the debuffed player's life.

edit:
Good to know, thanks!

Actually, the fire is ColfFlame damage, so unless you have another paladin using AM + Fire Resistance aura at thesame time you're not really doing anything when using AM + frost resistance.

(ColdFlame damage is like frostfire bolt, it picks the target's lowest resistance and deals that kind of damage)

Edit: if ColdFlame is not the right term used for this, then I apologize. However, I hope the message came through properly.

You'll find that healing through the small ooze damage is a lot easier than through the DoT + healing reduction. To not put it in riddles: cleanse as fast as you can, just make sure your fellow raiders are aware that they need to handle the little thing until it merges as would be the case if the cleanse wasn't spot on.
HoF on the tank is nice to have, but from personal experience I wouldn't have a healer mind me just to get it when kiting the adds.

It should be noted though that delaying a cleanse can be beneficial. sometimes one raidmember has to wait at the end of a green slime puddle, because the kite-tank is kiting the big slime through the puddle. In that case a second raid member with the debuff will also be there before the first one gets rid of his slime. It can me confusing if you cleanse those two instantly, creating a second big slime in the process. Those 2-stack-big.slime can also merge with the already-being-kited-big-slime, but, depending on your players, can also lead to confusion and player death. If you can delay the second cleansing enough you can prevent that.

If you're cleansing immediately, you run the risk of two players carrying little slimes towards the big one accidentally running into each other, and causing a second big slime to form. To minimize the risk of a second big slime, you want to minimize the amount of time that each little slime is active, which means waiting to cleanse.

moved my post to another section

We had the 'slimed' person call out when their slime was merging, and would then immediately dispel the next person, who would call it out, etc. Towards the end of the fight and the fast infection rate, we would just cleanse every other one immediately and let the other sit for a bit. I made sure to give the people who had the infection sticking on them some extra healing love, usually this fight is not very taxing on my mana pool so an extra Holy Light didn't hurt.

It's an ongoing debate for us whether it's better to let the tanks take multiple debuffs each time and only swap every 20-30s, or do quick switches after every Plague stack. The former is technically more raid damage, but with the slower swaps our paladins can switch beacons every time and focus on the raid. The latter is less raid damage but necessitates the paladins never coming off the tank(s), except when your beacon tank is up.

P3 is short enough (and you should be at full mana going into it anyway) that swapping beacons around is possible, and my personal preference is the slow tank switches, but it's not really been clear to us which strat is going to be preferable come hardmode time.

Another thing to keep in mind when considering crit vs mp5 and whether the extra output crit provides on both direct heals and Glyph of HL splash is relevant or not is to consider what will happen when hard modes are available. I suspect that for hard modes, like in Ulduar, many of the fights will require that you take as few healers as possible to be able to beat the DPS requirement (at least until everyone has 4 piece bonuses and full 264/277 gear). The fewer healers you have, the more valuable the extra raid healing that you can provide becomes because your raid healers are likely going to need all the help they can get. Plus, the combination of the 20% dodge debuff, increased raid healing requirements plus the scaling of tank gear and tank health pools means more often, the crit portion of your HLs will not result in total overheal. I just see the value of crit relative to mp5 scaling the more difficult the content gets.

This (pretty much) exact thing has been brought up before, I guess you didn't go through the whole topic, even though it is only 11 pages long. I'll provide you with a link to the post:
Holy Paladin Compendium for 3.3

And i'll even quote the part that is most relevant:

Correct me if I'm wrong, but Pungent Blight is, I believe, 100% shadow damage. Aura Mastery right before the explosion should help with the damage going out.

Pungent Blight is actually listed as shadow damage in the combat log, but it's unresistible.
Gaseous Blight instead can be mitigated by shadow resistance, so I suggest using AM immediately after a Pungent Blight to support raid healers when the damage is highest.

I think big ones can't merge with each other, can they? At least we've never seen two big oozes merge to form radiating ooze and it doesn't happen according to WoWwiki.

I would assume that you'd have to reach very high values of crit to make it dependable throughput for hard mode encounters. I would expect that DPS requirements are going to be tight just a bit more than they are now, given the fact that most people will be in 264 pieces after you kill Arthas in normal mode. And I personally doubt that you'll be able to cut back on healers on fights like Festergut Heroic.

Are you certain of this? The tooltip/wowhead entry suggest it is just frost damage:

Coldflame
Deals 6000 Frost damage every 1 sec.
3 seconds remaining

It is only Frost, indeed.

Big Oozes do indeed merge!
The stack handling works as follows:

Legend:
S - Small Ooze
B0 - Freshly spawned Big Ooze
B# - Big Ooze with # stacks (4 is maximum for stable, 5th will make it explode)

S + S = B0
B0 + S = B1
B0 + B0 = B1
B0 + B# = B(1+#)
B# + B# = B(#+#)

That means you can technically build a 8-stacked Big Ooze before it will blow by combining 2xB4

We had alot of fun (and by fun I of course mean headache) kiting around all the various slimes to make sure we didn't get an explosion for the Dances with Oozes (25 player) achievement.

On a more holydin related topic let me add these notes about the previous discussion regarding to cleanse / not to cleanse.
I aside from healing also had the task of assigning people in pairs to create B0's in front of the appropriate kiting tank on the go, and until we had approx. a B4 and a B3(so 14 diseases, give or take a few), the infection rate was very manageble, and cleansing immidiately was by far the better choice.
After that point however, you would simply have too many people infected at once, and thus creating unwanted chaos in your safe-zone.

What we did to finally get the achievement was simply to come to a cleansing halt when we reached two B4's, and have people run out in pairs when they were about to pop the disease.

For doing it normal mode, I wouldn't hesitate a second with stomping my cleanse button, as the boss should be down before the infection rate really gains speed.

I checked again today, as you can see I had Frost Resistance Aura active and I removed Mark of the Wild to be sure that resisted part of the damage was not caused by the fire resist effect of the buff; I still got a mitigation, so it's clearly frost damage.

How much of the extra crit you are stacking results in a crit heal? Holy Specced and raid buffed (2000 int) we're looking at

6% from Sanctified Light (Holy Light)
5% from Holy Power (All holy)
+0-8% from Conviction and Sanctity of Battle
5% Moonkin Aura/Ele Sham
15.18% crit from Intellect (taken from the initial post of this thread as the value of intellect in crit * 20, assumption made that this was at raid buffs)

Lets call that 31.18% to Holy Light. The highest critical strike rating I can get from available gear (without gems and enchants or taking crit/mp5 gear) is 1042 rating or 22.70% crit rating. That means overall 53.88% crit to Holy Light, and of that 53.88% only 2 in 5 (roughly) of your crit heals will have come from that crit rating you've been stacking. Does that really still seem so attractive?

The mp5 loss has been shown to be pretty large, and now I've pointed out how much of an effect that crit rating makes to your overall crit percentage and relatively what it does. Do you still maintain that stacking crit rating so that you gain roughly 50% extra healing in 2 of 10 casts? I honestly can't see what an extra 4000 healing which may or may not be effective IF IT HITS 5 people in splash of HL range can be considered worth gearing for, less so when you point out that it's going to be only happening every 6 seconds or so over a very long test. You can't rely on that for raid healing; I play a druid now and I can tell you that 4000 extra stupid healing every 6 seconds or so is pretty much the equivalent of the last tick of a Wild Growth which will be rolled on the melee anyway.

It might work for your raid force, I wont deny that. But if I ever got to play my paladin again I'd be asking our resto shamans if they don't mind me rolling against them on haste/mp5 gear.

The mp5 to crit comparisons I did a couple pages back ignored Glyph of Holy Light, yes, but the truth is Glyph of Holy Light significantly favors mp5 over crit. GoHL would affect 2/3rds of crit's throughput value (and the glyph can no longer crit, so no double dipping) while it would affect 100% of mp5's throughput value.

What to watch out for on the princes encounter:

Don't bubble when Taldaram is empowered. The fireball appears to need its target not to be immune or it will simply detonate upon activation resulting in a pile of dead melee. Note that this could be unintended behaviour seeing as we had the cone effect casted on the raid multiple times without the raid actually being faced giving him a generally buggy feel.

This piece is likely very intended in that it functions as a cone which is RSTS targeted. I think encounter design has moved beyond "face the boss away from the raid" when it comes to mitigating or negating an encounter mechanic.

Don't forget you can then cleanse the debuff.

Ok, thanks. So [Meteorite Crystal] remains on top of my trinkets-to-replace-Pandora-if-available list.