5x Druids + 5x Warlocks, if you're 10-boxing.
With Symbiosis, that is 10x Rejuvenation which should keep up anything that is not killed in a global.

10x Ferals will be a fun composition.
I will likely make the jump to 10 accounts, sometime this expansion.
An extra 5x Nature's Swiftness and an extra 5x Nature's Vigil...

I'll likely combine my 1x Holy Pally/4x Frost DK's... with 5x Ret Pallies.
Could be 1x Blood, 3x Frost, 3-5x Rets, and 1-3x Holy.