Many, many whites fled in the 1990s, a lot of them moving here, to Canada and Europe. The situation was so bad that Mandela met personally with whites' representatives, took care to provide extra security for the white enclaves, etc. Virtually all science, management and high-tech people were white (90% or so) and if they kept leaving, the situation would have resembled Zimbabwe of the past 20 years.
I have a good friend in SA who is a white woman. She lived here for some time, but moved back to take up an engineering job. She visits every two years or so, and the last time we met she said that she's probably moving back to the US next year. The election of the new president (a buffoon not unlike Bush Jr.) only made things worse. Now white has become a dirty word in SA, and she said the situation is now worse than it was right after the black came to power - wide-spread corruption, unbelievable crime rates, zero protection from the state for whites and blacks alike, unless you're in government or rich enough to provide for your own security.
She has a German shepherd dog that she never leaves the house without, and has survived several attempts of robbery, car hijacking and rape with the dog's help.