It would also be interesting to see what he means by "a subclass that does more with spirits and primal entities." It seems like the shepherd druid and the ancestor barbarian (even though they are different spirits than I think he means here) moved pretty close to that (and totem barbarian was already there). So what is left, a nature warlock? a primal sorcerer? Bard is naturally pretty flexible, so not so much need there, and the theurge didn't make it so "wizard with expanded spell list" is probably on the backburner for a while.