Recently missed deadlines underscore the tight schedule the country faces in getting 10 venues prepared for the start of the tournament on June 11, 2010.
The world financial crisis has added to the uncertainty although organisers insist the republic will be ready to stage a world-class event.
South Africa's 2010 World Cup Organising Committee chief executive officer Danny Jordaan told reporters this week his country would stage "the best World Cup yet".
"It's an immense challenge but we are in good ahape," he said.
However, South Africa could be victims of circumstances beyond their control, notably the global credit crunch.
Tourism officials in South Africa have warned of a downturn in international visitors and World Cup organisers continue to scale down the number of expected visitors, crucial to a successful tournament.
When South Africa first bid for the World Cup finals, it was estimated the tournament would attract about 900,000 visitors to the country. Now the predicted number is less than half that number.
Privately, organisers are cheering on countries who traditionally enjoy large traveling support to qualify and have been thrilled to see the strong start made by England, Germany and the Netherlands in their respective qualifying campaign.
At the end of last year, the world governing body FIFA also expressed its concern that the world economic downturn would adversely affect the number of World Cup visitors.
The cost of the 2010 World Cup has spiraled viciously upwards over the last two years with the South African treasury having to regularly boost the dedicated budget.
It is projected the event will cost some 12 billion rand ($1.19 billion), a massive jump from the price tag of 2-3 billion rand which was estimated in 2004 when the country won the right to host the tournament.
Jordaan said a massive increase in construction costs had contributed largely to the added expense. Extensive delays five years ago when local officials and cities jockeyed for power and influence after winning the bid have also proved expensive.
Four venues were supposed to be completed by December but Ellis Park in Johannesburg and grounds in Bloemfontein, Pretoria and Rustenburg are still not completed. They are scheduled to be used in June's Confederation Cup, the test event 12 months before the start of the World Cup.
The other six World Cup venues are scheduled to be finished in December but there is little confidence those deadlines will be met.
"We still have six months to play with so we are not worried about that," said FIFA general secretary Jerome Valcke on his last trip to South Africa before Christmas.
Celebrations are planned across the nation on Monday to mark the 500-day countdown.
