Honestly that is what I am planning on doing with my Main (Druid) once my shammy team gets to 70. The Moonkin buff, Earth and Moon debuff and Haste buff are pretty sweet. Don't forget about the +hit debuff that Improved Fearie Fire gives as well.

I think that a Moonnkin in place of a shaman would work fine. With all the talk about Totem of Wrath possibly not being stackable come the Xpac a Moonkin in the mix makes even more sense.