Adding a well working plugin for C4D from any render engine is a huge amount of work that takes a huge amount of time. With them adding support for ProRender I'd expect there to not be much more because of the huge amount of time making a plugin for a render engine takes. I see adding support for ProRender and a bad move for many reasons. 1) C4D had a ton of render engine available for use already. Of all the 3D programs out there C4D might have the most render engine plugins available. Yet another plugin is not what C4D needs. 2) ProRender looks slow and new. There is so much work that goes into making a good render engine having a new one is probably bad unless they have a huge team working very efficiently on it. 3) The time wasted on adding support to ProRender could have been used adding features people would actually want and use.
Other things that will probably be added is real time painting preview in bodypaint and some tools being multi core. It probably won't be integrated well with steady stroke and other features that would make people actually use it, so again a waste of time. I'm sure most have switched to useing 3DCoat, zbrush, or substance painter at this point anyway. If they do have things like steady stroke in there it will be a huge feature for me.
For the new core I would hope it means at least all tools would use multiple cores and everything would run faster. At the very least I'd hope the bool tool would use multiple cores. To help answer 3D-Pangel's initial question in the past we might have seen the mograph tool use multiple cores, a faster startup of c4d, and some other tools using multiple cores as a partial integration of the new core. They probably have been working on it for a long time so this for me will be the most interesting thing. Seeing how much they actually get done next year with that crew not having to spend so much time on the core will be more interesting.
MAXON switching to a system where you don't have to update every year for your copy of C4D to not become worthless would be great from my perspective. Their list of updates per release have been so ho hum that I could save a lot of money by skipping several releases and then pay $650 to upgrade. This would be bad for MAXON as so many people would do this, they would lose a ton of money. C4D has not have a I need it or really want it update for a long time. They know this, and are keeping the you must update every year policy because of it. There would be some money in the large number of people that might upgrade from really old versions to the newest one for $650. They would also be able to keep some users from switching to other programs because they are tired of paying $650 per year for features they will never use. To know if it would be overall positive or negative cash flow would be hard to determine. I could be wrong. Maybe they make more money by changing their upgrade policy.
That is the way I see things. I could be wrong. If they have anything like VR or something I'd be really surprised.