There are now 11 DNS servers for the .hk ccTLD which are placed in HK, Taiwan, Australia and USA. We still have 2 more servers to use before resorting to anycast technology for developing .hk server instances in other places.
Due to the increased business communications between HK and China and considering that Hong Kong is part of China, it will be beneficial to both HK and China if one set of .hk ccTLD DNS be located in mainland China. Likewise, HK can consider to host one set of .cn ccTLD server. At present, there are 6 sets of .cn ccTLD DNS in mainland China so at least there is a chance of setting up .cn ccTLD DNS in HK.
I have made the proposal to HKIRC.