The sprinter Frankie Fredericks from Namibia, the 800-metres runner Maria Mutola from Mozambique, and Penny Heyns, the South African swimmer, are among the stars who could perform well here. Haile Gebrselassie, the Ethiopian 5,000 and 10,000m runner, has blamed blisters for his non-appearance, but Johannesburg's 6,000ft altitude, which affects endurance events, is probably also a factor.
At the opening ceremony, President Thabo Mbeki stood up and said the games demonstrated the "fundamental renewal of our continent'' and embodied his vision for "the 21st century to be the century of the African Renaissance''. But what he meant, after South Africa's triumphant hosting of the Rugby World Cup in 1995 and its failure to secure the 2000 Olympics, was "please can we have the World Cup?" Britain, as a rival bidder, is watching.
There are sceptics - like the hundreds of All Africa Games athletes who were made to wait hours for their accreditation as the paper ran out in the machine. Among the flag-waving sportsmen and women pacing around Johannesburg Stadium during the opening were volleyball and table tennis players whose first matches had been cancelled. The baseball got under way belatedly at Randburg Sports Precinct because the organisers had forgotten to mark the diamond.
"Most of the problems were not the fault of the organisers,'' said a presidential spokesman, Parks Mankahlana. "We are ready for the 2006 World Cup,'' he added.
There are many elements of the these Games which are impressive - at least by the standards which this continent's athletes are used to. The 20 events in 10 days are sponsored by eight companies who are providing about a third of the pounds 15m cost of the Games.
Security is tight and a special "village of the stars'' has been built to accommodate the athletes on treeless wasteland next door to Alexandra township.
It is a windswept place, whose 1,700 small, brick houses, with electricity and carpets, will be sold cheaply to ordinary South Africans after the games. They are actually bleak, little boxes with corrugated roofs, in which South Africa would never dream of putting European or United States athletes.
But this is a two-speed world, and the Rwandan cyclist, Faustin Mparabanyi, 29, was impressed. "My bed is comfortable and the transport seems adequate,'' he said as he went to complete road-race training.
Norbert Kwagmi Amefu, a 29-year-old member of Ghana's tae-kwondo team, was less enamoured. "This is my fourth All Africa Games. After Kenya in 1987, Egypt in 1991 and Zimbabwe in 1995, I must say I am a little disappointed. The queues for food are very long, and there is not enough for everyone to eat.''
The 10-strong Mauritius judo team was pacing round the village's dusty coach park for a vehicle which might take them to a shopping mall. "It is early days,'' said Marie Saint-Louis, "but the South Africans will have to be incredibly good to out-do the Zimbabweans' friendliness four years ago.''
To Beatrix Callard, a Namibian hockey forward, the South Africans were "doing their best''.
The first All Africa Games were held in Brazzaville (Congo) in 1965 when 30 countries took part in 10 disciplines. Until the Harare Games in 1995, when South Africa took part for the first time, Egypt had always topped the medals table, followed by Nigeria.
This year, the South Africans, who have a team of nearly 600 sportsmen and women, are expected to dominate again. But the games, billed by the hosts as the "African Olympics'' and "the last multiple sporting event of the millennium'', are rather in the B-league. They have never produced a world record and, this year, because of the high altitude aspect, could only conceivably break that pattern over a short distance race.
A record or two would be desirable to bring the Games to worldwide attention, but the South Africans are acutely aware of the unwelcome attention their organisational skills will receive if a prominent athlete is caught up in a crime.
Consequently, using armoured vehicles and 5,000 police and soldiers, some on all-terrain motorcycles, the organisers are trying to cocoon the visitors from the violent realities of the crime capital of the world. This is one of several sticking points which could blight the World Cup bid.
If none of the visitors in the coming week is mugged, or stabbed, or caught up in another car hijacking - a Games vehicle was hijacked in Soweto on Friday - the South Africans will feel they have done a good job. What they are less likely to appreciate is that people unused to high levels of crime find it disquieting rather than reassuring constantly to be surrounded by guards.
Old habits die hard and South Africans - be they civilians or in uniform - tend towards officiousness in sticky situations.
Most of all, with 6,000 enthusiastic athletes in town who, as Africans, largely feel great affection for this country because they and their government supported the African National Congress in its fight against apartheid, it would be nice to feel that South Africa was in it with its whole heart.
In reality, only the World Cup bid really matters, as evidenced by an opening ceremony which was entirely in English and did not even pay lip service to the non-South African presence. South Africans, generally, because of years of isolation, do not care much about the rest of the continent, nor are they quite sure what the African Renaissance is supposed to be about.
When the Seychelles team entered Johannesburg stadium on Friday, all the South African television commentator could think to say was that the country is "a great holiday destination''. Several other nations fell under the "war-ravaged'' stereotype.
South Africa loves its football, so an Under-23 tournament is part of the games. But a real test of this country's commitment to organising a large-scale sporting event - which should be watched by those deciding on the World Cup bid - is how many people turn up for, say, the athletics.
Every athlete has been handed a green leaflet in six languages with "helpful hints'' to make their stay enjoyable. It signs off with: "Hamba kahle uphinde ubuye'' (in Zulu: go well and come back again soon). We'll see.