Specifically looking for reputation grinds:

Leather armor sold by vendors (not PvP)

Exalted with Wildhammer Clan gives you a nice set of purple 85/359 gloves (Stormbolt Gloves). Alternately purchase the blue Sticky Fingers which is 85/345 for 1650 JP.

85/346 Quicksand Belt - Revered with Ramkahen

83/333 Sly Fox Jerkin - Honored with Guardians of Hyjal

Earthen Ring (revered) needs to be worked on in order to buy the head (arcanum) enchants for bears. Kitty druids will need to grind with Ramkahen instead.

Shoulder enchants sold by D'lom the Collector (Therazane), require honored or exalted.

Revered with Baradin's Wardens gives you Spear of Trailing Shadows, but you also need 85 Tol Barad commendations. Easier just to get the Elementium Poleaxe crafted.

Revered with Guardians of Hyjal gives you Acorn of the Daughter Tree (necklace).

Revered with Therazane gives a ring (Terrath's Signet of Balance).

Exalted with Earthen Ring gives a very nice purple ring (Signet of the Elder Council).

Summary:

Earthen Ring - head enchant for bear (Revered), 85/359 purple ring (Exalted)

Guardians of Hyjal - 83/333 blue chest (Honored), 85/346 blue necklace (Revered)

Ramkahen - 85/346 blue belt (Revered), head enchant for kitty (Revered)

Therazane - blue shoulder enchant (Honored), 85/346 blue ring (Revered), purple shoulder enchant (Exalted)

Wildhammer Clan - 85/359 purple gloves (Exalted)

Notes:

The arcanums are BoA, which means that if you get to revered on one character, you can buy the arcanums and send them to your other characters. But currently, the other character *also* needs to be revered with the faction that hands out that particular arcanum. (Not sure yet whether this is a bug or they aren't supposed to be BoA.)