I agree with Cutman for a change. The new super fast C4D when it comes will look much the same as it does now and function much the same. C4D is a modular type application so modules like MoGraph plug into the core application. A lot of work and thought would have gone into how to rewrite the core without having to rewrite the modules. Some however like modelling and Bodypaint have likely been largely rewritten.
Re R19. Think I pretty much nailed it with my predictions. I picked it wouldn't be the big one, Prorender would be big feature, some MoGraph enhancements, no UV / Bodypaint enhancements apart from some token gesture stuff (grow / shrink selection), no modelling enhancements apart from some under the hood stuff then the usual list of assorted enhancements.
So for R20 here goes: Super fast object handling, nodes everything including materials (if you want), updated / rewritten UV tools, proper symmetry modelling. Possibly with R20 or coming later a replacement for Thinking Particles. I would expect with the enhanced node system to be able to do some cool procedural modelling type stuff / animations but you'll need to be willing to put some time into learning how all the nodes work.
Re plugins for R20. Since the new core will be fully functional plugins / 3rd party renderers will need some major work to work with R20. Just speculating big time here.
Anyway, fun times ahead.