I'm personally staying in HK (bought a flat in 2008) but I believe many expats are going to be leaving due to rapid loss of freedoms and opportunities that normally exist in an international financial centre with a free flow of information.
Before I immigrated to Hong Kong in 2005, my parents warned me that eventually there could be a full Leninist takeover. They both escaped from an Eastern European Communist state. They told me a lot about their experiences when I was growing up, and while their experiences didn't seem very helpful growing up in a pluralist society it is quite helpful now when adjusting to the "new Hong Kong".