While Hong Kong might be the Gateway to China and a great place to invest in Property, the Pearl River Delta is dotted with somewhat Environmentally Friendly Factories (Chinese Standards).
A few years ago when I was there I mistook cool mist around the hills for smog (a not-so-happy-with-the-takeover local corrected me quickly). From the pictures all over the internet now, I'm guessing them Super Penthouses aren't as attractive as they used to be.
Unfortunately while the New Hong Kong Government seems to be handling the takeover pretty well, I doubt they have any pull on the Mainland Chinese agenda with Beijing being the focus until the Olympics.
So there you go Mr. Foreigner, please buy more Singapore Property. If it helps, you will be contributing to the Mr. Realgossip retirement fund.