My current Druid arena deck is 5 - 0. I think I'm getting good at this. I imagine I'll hit the same wall I did with my last Mage deck, maybe sooner. I've got a lot of quality minions, but I have zero AoE. I have a lot more taunt, though. I might post my deck list tomorrow if I have more time. Choices were a lot tougher for this deck, and it has some weird spikes on the mana curve. I took an Ironbeak Owl just to have more 2 drops over a huge spike at 5. So far it's been useful to have a cheap silence, but who knows.
Oddly enough my closest match came fighting a Rogue who coined into his hero power the first turn, and proceeded to use both charges on my face. No deadly poison, nothing. Just two damage out of the coin. Got me down to 13 before I had him to 20, but then my heavy taunt started coming out, and he just couldn't follow through to the end. He might have had me with some crazy Leroy combo, but he couldn't knock down my last 12 health.