I RAF'd... Balance Druids, Beast Hunters, Disc Priest and Elem Shammies to 60th.

I opted to go with 5 shammies for my first team, but dropped one for a pally at 72nd.

Recently, I'm attempting to go with my 70+ single box toons, but as a 5-box team.
This is Feral Druid, Demo Warlock, Marksman Hunter, Elemental Shaman (from 1st team) and Disc Priest.
The team isn't as fun as Disc Priests or Balance Druids, but they're all 70+ with Epic Flyers.
I'm really enjoying the gold from the Daily stacking.
75, 74, 73, 70 and 70.. is a lot closer to 80, then either of my 60's teams.

For druids, I'd definitely level them 5x Balance.
I'd strongly consider dual spec on two of them, one to Feral and one to Resto.
Then you have the option of heroics or tougher quests.

Balance x5 is really fun. Mass Treants, Hurricane, Rejuv/Regrowth/Lifebloom x5 is immunity to damage basically, 5x Wrath drops almost anything in two volleys, 1x Starfire does the same. Starfall x5 will be sick. Moonfire and Insect Swarm is 10 quick dots.

Every toon is either Moonkin, Tree or Bear, for massive armor in PvP's.

You'll have a weakness to Fear Bombs, but destroy almost anything you detect.
With cat and stealth, you can do stealth instance runs or have an edge in pvp.

Gathering herbs or ore does not require you to drop Flight Form (or didn't in BC anyway).

The druids are a ton of fun, but so are the disc priests.
Pretty sure I'll level both groups to 80; they're too fun not to.