Google has made its maps services available in Chinese Simplified language awhile ago. If you drill down onto details, some of the large cities like Beijing or Shanghai have much more street details on the maps than other less significant places in China.
Hong Kong as one of the major cities of China (in which it was re-acquired from the British in 1997) does not have much details on this version of Google maps. Rather I expect Google to later release the Hong Kong version of maps. It will make more sense, as Hong Kong’s Chinese language has always been in the Traditional fonts while the rest of Mainland China is using the Simplified fonts.
A link has been added to the Google China (Guge) homepage alongside the existing links such as web search, images, and news.
I expect this new Chinese Simplified version of Google maps will become much more popular than its Standard English version, as the majority of Chinese users still prefer using services of their own language.