Druids have two things that were not traditionally in DDO: Shapeshifting, and animal companions.
Animal Companions
The animal companion issue seems to be under control. NPC UI has improved tremendously over the years, to the point where I trust the devs to make a DDO version of a druid's animal companion.
Animal Form
DDO still completely lacks shapeshifting. That's a problem. If druids are added, I want them to have actual shapeshifting. That is, I want to control a grizzly bear with a boatload of hitpoints, a vicious physical attack, and restricted use of items and abilities.
The Pale Master undead forms have been a step in the right direction, but these are still a long way from what druids need. It's still the same character models and animations. Also, a Wraith Form melee build still uses the same items, weapons, and spells as before. His melee DPS increases as he farms Greensteel or Epic weapons, same as with every other class.
Whatever the devs have in mind, I'm hoping they'll start testing shapeshifting with other classes first. Give Wizards and Sorcerers the spells
Polymorph and
Shape Change. If that's too much power for one spell, add Dragon Disciple as a prestige enhancement line for Sorcerers (they really do need a PrE; Archmage DCs are putting Sorcerers to shame). Just modify it from PnP rules so that at higher levels, it grants the ability to transform into a small dragon. Bam! There's your shapeshifter testing ground, and you only need one new model and set of animations.