I would like to request an addon, dealing with the following:
Display the status of your shaman's Lightning-, Water- and Earthshield.
Nothing more, just a tiny mod dedicated to that only.
At the beginning, I think it should be sufficient to check for Lightning and Watershield on yourself, and give a little button on the Interface that is Moveable, just like any buff or debuff icon. Maybe already with charge count on it.
In the next step, make this button moveable, scaleable, maybe give it different states, such as view on solo/party/raid/pvp, transparency, whatever.
I think the most difficult part will be to watch over the Earth shield, as it is on a different target than the current player.
If theres already a mod like this existing, I'm sorry to wasted your time and please tell me about it ;)
it does not track lightning shield however. still, a very nice addon and it probably comes closer to doing what you want than anything else. if you are resto you will rarely, if ever, be using lightning shield anyway.
I've been in communication with the author of beSch, and will soon be releasing an addon based on beSch, but with an in-game configuration, and additional features such as the solo/party/raid/arena/battleground view states you describe, plus a few other things. I also plan to track Lightning Shield in addition to Water Shield and Earth Shield.
What about the ZOMGBuffs!!! self-buff module? It'll warn you when you need a new shield.
To show how long the shield would last, you could use a separate group in Elkano's Buff Bars just for shields. I have my EBB set up so I have 3 groups: long term buffs, short term buffs and attached in that group but with a different color: shields.
The combination works pretty well for my shaman and my priest.