TBD as Joppa likes to say. They are adding some ability functionality to other classes first that will affect how the Druid works. So the order from what I understand is Enchanter charm is the next big thing, then Warrior banners (this affects Druid because of their tree and probably their passive pet), and then sometime after that we will see Druid. Druid and Bard are the last 2 classes and Bard will probably be after Druid from what I am hearing. You are not going to get an exact date yet so I hope that helps!
Not as soon as you would like it to happen is prob the most sobering answer you will get.