1. Do something about Form of the Fearsome Brute, the attack animation, the look and lack of weapon, the bonuses.
2. A set or several sets of equippable items for Druid Shifters, like that belt in PoE1, hard to find or obtain, but rewarding and fun.
Yea, I like transforming into stuff ._.;;
3. Longer, deeper dungeons, as was already mentioned.
4. Cosmetic Slots and/or the ability to remove/add enchantments to items such as clothing.
5. Robes, we need more, preferably with some detail if they're unique, like Huana clothing.