Occupy Central organisers and pro-democracy politicians in Hong Kong have recently felt the need to deny accusations that they have been fraternising with Shih Ming-teh, the so-called godfather of the Taiwanese independence movement. Even the most rabidly anti-Beijing elements here won't say they support formal independence for the island and polls show the vast majority of Chinese Hongkongers oppose it.
As a foreigner whose interest is purely academic, I have no opinion either way, but I'm aware that for most Chinese, Taiwan as an inalienable part of China is non-negotiable.
Most scholars agree the first historical references to Taiwan were to a certain "Yizhou" mentioned in third-century Chinese texts. China was then divided into three states, and a fleet was sent by the northern Wei Kingdom in search of Yizhou, which the governor of a coastal county in the southern Wu Kingdom had described as a lush, tropical land about 750 kilometres southeast of present-day Zhejiang province and inhabited by peoples different to the Chinese in appearance and customs.
These and later references to Chinese exploration and colonisation are used as proof of China's historical claim on Taiwan; predictably, pro-independence detractors question the certainty that Yizhou was indeed Taiwan.