香港公民去美国旅遊

The answer is yes - you still need a visa.

1. A bill was introduced to make Hong Kong as a country for the consideration of Visa Waiver Program. It never gets passed.

Even the law has passed, it does not provide visa-free travel to people from Hong Kong (as it is a discretion by the U.S. Department of Homeland Security). It simply means Hong Kong is eligible for the consideration of the program only.

2. Since the Snowden incident, it is unlikely that the U.S. will allow Hong Kong to join VWP.