Okay, I admit, I have no clue as to what the posters end up talking about... yes, enhc shamans are like rogues in that they can dual wield and do damage, but the buffs and the option of self-healing are completely independent of a rogue's abilities. As an elemental shaman myself, I am always ready to heal someone if there is a problem going on... the tank took a couple of criticals or a volley spell just went out, through a healing wave or chain heal. We are different from Boomkins in that very respect... we do not have as large a crit buff precisely (I believe) because if needed, we can immediately cast a healing spell as soon as our finger can hit the escape button, no global cooldown, no mana wasted shifting in and out.
I admit I have a friend who is an enhc shaman that has tanked some instances in BC, and that I in my pre-BC enhc days did offtank and pick-up tank when the occasion called for it. It was luck that we could clear places like Mech with the shaman tanking and forget anything beyond normal instances at 70. The only use I have for tanking now is for Frost Shocking a mob coming at a caster and dragging it back to the tank so the tank can pick it back up, and that happens only on occasion.
I think it is not the class that is becoming specialized, but the instances themselves and the mobs that we are facing are forcing the issue. Our gear has been mail for 30 levels now, and there has nary a piece of it with defense or parry on it to speak of. The talents in the enhc tree that would be useful for tanking are about as useful as, to quote Rip Torn, a poopie-flavored lollipop because of the very reason that we are still the same gear and how lopsided would it be for us to have +str, sta, crit, parry, defense, dodge, int and spell in one piece. The offtank role has been officially passed off of us because of the level of disparity in the mobs, crowd control, and multi-mob tanking.
The issue is being forced in many other cases as well... holy spec pallies can't be expected to compete with rogues or mages in dps or to hold aggro. Neither are 2-hd mortal strike warriors expected to tank a heroic and be able to do it without having some serious gear augmentations and some extra healing thrown in.
The game is becoming more and more nuanced and requiring more specific roles for a party to be effective, but we still fill three of those roles effectively. DPS either as caster or melee, a main-healer, and in any one of those specs, we are far and away the most versatile support player in the game still. Buffs for all and damage or healing at the click of a button, no wait, no muss, no fuss.
I feel sorry for those other classes that only have different ways to play their one limited capacity... hmmm, should I shoot little blue things, big red things, or lots of little purple things... I'll have to go ask the gnomage next door....
That my friends, is what I love about the Shaman class. John Morrison may be the 'Shaman of Sexy', but we are sexy all the time just for being Shamans.
BTW, in response to the original post, I still use Smart-Buff. Find it on Curse of course, and it has the options of setting any number of things for the Water Shield. My current setup announces to me on the screen and audially when my shield is running low or out, and I can simply roll my mouse scroll either direction for it to buff... reaaaaaaally handy. Also helps if you have multiple buffs like my druid does. Once you set up which buffs you want and when (you can set it up for solo, in combat, out of combat, party, raid, etc.) you just keep rolling the scroll until you're all buffed up.
Cheers, and happy hunting!