I sat in a Discovery Sport at my dealership yesterday and talked for a while with my service rep. He has seen the new Discovery. What will be the 2016 Discovery. (No more LR4 but we already knew that.) The Discovery will look like a larger (longer, taller, wider) version of the Discovery Sport. One thing he pointed out is that they are going to keep the design of the 2nd and 3rd row seats/cargo area. Well, some minor improvements such as the middle row being able to slide forward and back. But the ability to become completely flat and configure it a zillion different ways is something owners really like (like me) so that will stay.
He also said that, as most already know, they will be introducing turbo-diesel engines in the RR and RRS next year. Probably not in the Discovery in 2016. But very likely later. In fact, it is likely that all of the lineup will have TD available eventually.