Underwhelming if you ask me. Somewhat useful to justify Hand-druid, but kinda weak for the 3 mana spots. After seeing it in action in today's live stream, I retract. This card seems promising and is a great support for Hand-Druid archetype.
Druid doesn't have any armor synergies except for 3/6 taunt for 4 (unless another one gets revealed tomorrow), so it's not needed much. Might be playable but druid has a lot of other ways to gain tons of armor, if he wills it.