You could run a Druid, dual-spec.
One spec would be Balance, for PvP.
Another would be Feral, for PvE tanking.

Combine that with four Elemental Shaman.
You could possibly dual-spec one of those Resto, if you wanted a dedicated healer.

If there is no interest in PvP ever...
A Prot Paladin instead of the Feral might be a little easier.



The dual-Healer thread is a decent idea as well.
Consider any tanking class you would like, other than a Prot Paladin.
Combine that with dual Holy Paladins.
And two DPS classes, probably Elemental Shaman for the utility with totems.
Both Pallies make the shammies their Beacon, so they receive half healing.
They have the talents to receive significant heals when healing others.
And you have a lot of buffs (Kings + Might + 2 sets of Totems).
You could drop one of the Pallies for a Disc Priest if you want... who would then primarily Smite dps, which would passively heal the party via their Atonement talent... Priest brings Shields/Pain Suppression/Fortitude buffs...