I'd say Druid's would probably come last. I honestly doubt DHs and Evokers will ever come to all races, I think the intent would be all classic classes to all races first. And druids have, by far, more model work than Paladins: bear and cat form with 4 or so colourations each and a default Moonkin form.
Paladins need a mount model. Granted the mount is probably going to be more detailed than the druid forms. And shaman is a single totem model with 4 elements slapped on.
Of course, they could also surprise us and give us all 3 of those classes (due to the increased staff in the dev team) at the same time to wrap up DFs story: Primalists are parallel to new Shamanism teaches amongst new races; new Paladins are enlisted by Tyr's Guard; and Wild Gods probably will spread teachings of Druidism now that the Dream is safe and far more accessible to adventurers.