Could also be from a previous crit heal from a discipline priest. Divine Aegis looks much more 'bubbly' than PW:Shield does.
As a druid tank, I prefer not to get shielded on the initial pull. I'm not all that knowledgeable yet on the mechanics. I know I get rage from dodging, critting, but I also believe I get some from being hit.
As a rule, when I heal on my priest, I tend to not bubble the tank, except when moving (4 horsemen for example) or 'oh crap, tank's going to die'. The protection of the shield + glyph, has saved a few wipes.
As a warrior tank the only times that I have rage starvation issues is during AoE pulls where I am cleaving every single swing. I can't recall on any 3-5 heroic trash mob pull where I have no rage. On boss pulls one hit eats the shield and then some. Wrath is a rage rich environment as a warrior. My biggest problem with my rotation right now is dumping all my rage.
I think the aversion that warrior tanks have to not being shielded is a hold over from pre-Wrath where it was a no-no.
Spam shields all you want on boss fights after i have my heels dug in, but please not on a pull unless the boss is just going to one shot the shield off of me and I have enough rage to get that first SSlam/devistate in there.
I think most view points on this subject are pretty well covered in the thread, I just though I'd add a personal point. My fiancee plays a priest and used to shield me in some of the less opportune times (AoE pulls, low rage situations etc). The solution is quite simple, don't start a fight with your healer or start chest thumping on how you are so good at this and know everything about that and just keep your stupid shields to yourself... just quietly click off the buff and move on After the instance bring it up and mention that in some situations is a good tool, but be careful to look at your tank's rage bar first. If its low, don't shield. If its high and the tank is getting hit regularly, go for it!
PW:S is a big no no in heroics. Especially prior to engaging a group or single mob. It gets worst with a Disc Priest since they will proc Divine Aegis.
I ran heroic VH just a few days back. I had to literally swap some of my gears in order to obtain enough rage to keep the AOE bunch of dpsers happy. With sufficient avoidance, u will notice the PW:S staying with u for a while.
I'd recommend only PW:S the tank in a 'oh shit' situation. Else just throw any HoTs or just spot heal your tank.
Shielding your tank prior to a pull is laziness. You can pre-heal and cancel it.
I am but just a warrior.
For me its not a big deal at all. Mitigates some burst dmg and such, and if my healer is comfortable with it then I dont bother in their rotation. Personally, I feel that if I'm at zero rage before each pull, im not going fast enough. You shouldnt be burning rage that quickly at the end of a pull.
I like to stop at around 10% of the mobs health, take a few hits while the DPS finish it off, that leaves me with about 20-30 rage, just enough for a SS or HS.
I had Maexxna running wild on me the other day because of 2 parrys from the boss, and 2 dodges by me, followed by a block, with the rest of the damage absorbed by a shield that a PuG disc. priest casted on me... Not fun. And in 5mans, whenever i see a bubble of any kind on me, I click it off. period. In case a situation arises, which warrants shielding me, I will be busy enough hammering my OH SHIT buttons, so I won't have time klicking it off then
I'd prefer them to not do it but I've never been that anal about what the healers think they need to do (My main up until LK was my resto shaman)
If your dps isn't balls to the wall from the second you pull it's not a problem.
And situations where a bubble would save your life are few and far between, but I'm not going to be sitting there clicking off bubbles just to spite the priest, at least all the priests I run with use it when they plan to not be healing, like shackling a mob or they are focusing on healing someone else just to buy them a second of not worrying about my health.
It really depends on how your tank starts the fight. as a warrior i never have an issue with the boss running towards the person who shielded me because i start every fight with a bloodthirst then a charge and immediately shield slam when im in range. the only boss fight that i wish not to be shielded on is saph, assuming its the first pull, i run in before his spawned and spam SS until it hits, however if a totem is down or im sheilded there is a rare chance that he might turn twards the raid and start off with a cleave, and thats always bad (its only ever happend to me once.. i was having a bad day)
I've never had problems with being shielded before pulls, even in BC or Vanilla WoW. In Wrath it's also much less of an issue with Bloodrage/Charge giving 25-45 rage right off the bat to work with.
It's slightly more of an issue on my Druid for AoE groups since he can't TC etc. but I can still conserve rage/enrage before a pull and pick stuff up just fine with Swipe or Berserk Mangle.
Keep in mind (virtually) all bosses are tauntable, so it's hardly an issue to taunt it back on you at the start of a fight.
I get annoyed by Deathknights taunting bosses off me for some god awful reason (Is it bad I like to let them die just to spite them?), not Priests/Pallies bubbling me on the pull
It's a little different when I'm not running with insane guild DPS who like to pull aggro whenever possible, but during trash packs rage certainly does matter, especially seeing I want to save bloodrage for emergency low-rage thunderclaps.
Don't get me wrong, I would never klick off a shield in any kind of tricky / dangerous situation. But there is just no reason to shield the tank in a "normal" pull during heroics, where I'm begging for rage to begin with.
Bottom line is.
if the tank is getting smashed hard enough to warrant a shield, then he won't complain about it because he won't be getting rage starved
if he's getting hit lightly enough that the shield would rage-starve him, he doesn't need the shield.
It's very helpful if the boss needs to be moved into a position away from the starting one or where your dps/healers need to get to a specific point. Fights like Heigan, Gluth, Sapphiron etc where you and your healers are on the move a bit at the start and your dps isn't going totally crazy right from the word go. Any buffer to stop an insta-gib in case all your healers are moving at once is a safe bet. On stationary pulls though use it as a mitigation tool rather than a starting move.
Raid Leader, GM and Meat Shield. Shadow, Firetree Horde
this... never happens.
The bottom line is PW:S, don't do it.
If you feel that you MUST do it, at least tell them (and the dps) that you are going to do so.
Now if only I could get my pally healers to stop BOPing (i suppose it is properly HoP now...) me on accident in the middle of fights... /grumble
If you're looking to PW:S before a pull, all your rage issues could be solved with a mighty rage potion before the pull. So long as you get the potion in before you enter combat, it won't effect your in-combat timer (but you won't be able to chug another pot for 2 minutes)
In my experience tanking i can not remember a shield that i received that i was happy about. Granted in some oh shit situations i might have received one, but i definitely did not notice then. The shield is basically even if warrior tank uses rage abilities nerfing his threat and the initial threat lead for a tank is very important so he can use more mitigation abilities ready to go when situation arrises as opposed to having the dps right behind you and all you can do is threat race. I raid heal as well if you think you are forced to pre heal a pull either you shouldn't be there and have some work to do yourself, or that tank really needs some work.
my 2 cents