should dump that second ele shaman for a lock or boomkin imo.
Unfortunately a Warlock is one of the only classes I DONT have at 80. My highest is 53. And I have never been able to master the Boomkin, even before 4.0.1.

The only problem i can see is that with you beaconing the mage, you lose your main holy power gaining resource for WoG etc.
It hasnt been an issue YET, but we'll see how it goes in Cataclysm. I may have to adjust later.