As Capetonian says, South Africans have been shafted by the UK govt for a fee and so I expect the SA govt to return the favour. I have many SA friends and they can ill afford the Visa when travelling/staying here is seriously expensive for them. As far as I know, the Brits have not instituted a similar scheme against the other former colonies of OZ/NZ/Canada.
I recall in the early 1990s my lady needed a Visa to visit India, even though it was clearly a bureaucratic exercise just to keep people employed and generate income to pay for their employment.
In the current financial crisis, I expect many more countries to do this.