IBM will probably be in it for the long run and if companies can use the OO.o components for their own products they might get traction over time.
Maybe that is the future of OO.o, a lot of building blocks that can be used to build your own office application, but most of custom UIs will be closed source and the old UI will stay around forever. But if that is the goal then the Eclipse foundation might have been a better parent.
Let's look at this in 2 years. I am not sure the DF will bring a newer more modern and faster UI to LibreOffice .. and lets face it, that is what is needed. Otherwise people should just start to contribute to Calligra, which has way better foundations.