They'll likely become autonomous provinces of China. It makes sense. They are too unique to be annexed and too small to be countries. I'd imagine china would extend taxes and certain laws to them, but they would ultimately decide how things work inside their provinces. Also, I believe borders will (should?) become open to facilitate trade and development. China is no longer just China, but the sum of all the cultures inside, like EU or the US, in a way (I know EU is totally different from the US due to the political and financial systems, but somewhere along those lines of union).