Well for heroics you need revered rep with 5 factions
Cenarion Expedition (Coilfang)
Sha'Tar (Tempest Keep)
Lower City (Auchindon)
Thrallmar (Hellfire Citadel)
Keepers of Time (Caverns of Time) (This is easiest. Do the full quest lines for KoT and you will almost be revered. 8K rep for one of the quests).
Then if you want the Earthwarden you will need Exalted with CE, although with buffs coming in the next patch, BSoS will become a much more viable tanking weapon until you get some drops. (They are adding 39 STA to it on top of the 500 Armour).
Also, you can get some very nice druid tanking items from quests so you could try doing those for the rewards (if you haven't already) to break up the rep grind.
Check out:
Verdant Gloves
Umberhowls Collar
Manimals Cinch
Cloak of the Valiant Defender
All of which come very highly on druid tank gearing sites. eg.
Bear Mitigation Also, you could start thinking about getting attuned for Kara
I think the best thing to do is make a list. I did. Something along the lines of
Items I want, Mats I need to farm, Quests I need to complete, Rep I need. Then mix and match to stop getting fed up with a continuous grind on one instance.