I really doubt we will see 4th specs (at least wholly new specs, not guardian druids). Blizzard has a terrible time trying to balance all the specs as is, and this would create 11 whole new ones that need to be balanced. I think we are likely to see the normal new class and or new race release. We might also see certain specs changed to add variety, but I don't think every class will change. We might see Demonologist locks go full tank, or something similar but not every single class, that would be a terrible waste of development time, when people really want new things.