I've also swapped out my 4th Shaman for a Warlock. I tried my druid in there for awhile and I just find them horrible to box.

He does provide nice buffs tho. Have you considered making the Elemental Shaman dual spec resto?

Then just using the Resto shaman for hard fights and the rest of the time you would have:

Arcane Mage, Boomkin, Shadow Priest, Ele Shaman.

That way you would get replenishment too

I use:

http://raidcomp.mmo-champion.com/?c=...00000000000000


To compare buffs and see things that wont stack with each other.