I think the lagacy goes beyond just the Chinese government. I was a young child but vividly remember "Tankman" after all of these years. I think the entire tragic ordeal may have influenced people around the world to become active participants regarding the injustices of their government. Watching the footage as a child, I felt as if Tankman was extremely brave, and I had never seen anyone so brave and willing to sacrifice their lives for what they believed in.
It would be lovely to say that after these demonstrations that China had opened up more, however, I have to agree with other editors when they say that actually Tiananmen Square actually had a negative impact on human rights and freedom of protest in China. More recently, we have seen Google caving to Chinese pressure restricting freedom of information, and the Shanghai Olympics have been used as an excuse to forcibly evict thousands, not that we have had access to full information about it. When we talk about legacy, we normally refer to something positive, but I think China has only become more closed rather than less closed in the interim.
If these demonstrations have had any legacy, it is to make the Chinese government less open to democracy and dissent. The Chinese people, understandably, are reluctant to express any dissent because they know they may well be crushed if they do. There has been no positive legacy of the demonstrations because they did not succeed in causing China to move toward more democracy and openness.
The image of the "Tankman" is a powerful one in the West, so much so that it is regularly listed by Western media as one of the most important photos of the 20th century. Perhaps one legacy is that it inspires us to believe in the power of the individual. On the other hand, I think a cynical argument against the power of the individual could be built around the image of "Tankman."
I think that the fundamental legacy of Tiananmen Square is to show that the Chinese government has a problem with acknowledging human rights. The world has become more globalized in the last 20 years. In that time, more democratic reforms and practices have swept over the world. The emergence of the European Union, as well as democratic movements in Africa, and most recently, in the Middle East has demonstrated that democracy is becoming the government that nations rapidly embrace and democratic principles are becoming nearly universal. Yet, the legacy of the Tiananmen Square protests has to be that China, as a government, has a great deal of distance to travel in following the world's lead on the issues of human rights and democratic reforms. As China becomes a leading economic force in the world with the second largest economy, there has to be an understanding that China's past does not reflect the world's future. Brutal repression of human rights and democratic principles, such as what was seen in Tiananmen Square 20 years ago, is not where the world, for the most part, is right now. If China is going to be seen as a world authority, the Chinese Government must embrace all of the baggage that comes with it. Part of that is ensuring that what it did 20 years ago to dissidents and student protesters is not repeated and that it must hold itself to a higher standard of human rights because its past does not reflect this.