So I completed Deepholm over the weekend, which left my Druid 20% shy of lvl83. Since there hasn't really been a pass over the zone, I don't expect the xp to be too meaningful and I assume that you'll be hitting lvl83 so you can then move to Uldum.
There's a great variety of quest-types in the zone, and even a cameo of Millhouse Manastorm (who I've also seen during a solo ninja run of the Stonecore instance).
The zone has you searching Deepholm to recover the fragments of the World Pillar, which was shattered by Deathwing as he ascended and broke through the planar barrier into Azeroth. Without the World Pillar, Azeroth is destablised and is being drawn down into Deepholm, the elemental plane of earth. Thrall is up top holding back the vortex at the Maelstrom, but you are tasked with bringing the fragments together so that the Earthen Ring can mend it from the other side.
As is so for both Hyjal and Vashj'ir, phasing tech is everywhere and the zone is very often changing due to your efforts.
I really enjoyed this 'journey to the center of the earth' feel, and am looking forward to the suspense and ambience being polished even more.
As for Balance Druids, they've barely been touched other than a slight rearranging of talents. Hopefully I'll be tackling Uldum and its air elementals with a freshed Moonkin in the not too distant future.