Mr Zuma effectively replaces his predecessor Mr Thabo Mbeki who helped broker the historic power sharing agreement on September 15 last year, leading to the formation of an inclusive government in February.
But Mr Mbeki was criticised for being soft on President Robert Mugabe with some of the Zimbabwean parties publicly declaring that they no longer had confidence in his mediation.
Last week, Prime Minister Morgan Tsvangirai suspended his three-week "disengagement" from the power sharing agreement with Mr Mugabe following a mini regional summit in neighbouring Mozambique.
The decision was largely influenced by Mr Zuma’s entry, which was immediately hailed by Mr Tsvangirai’s camp.
Negotiators from the three parties in the coalition – Zanu PF and the two formations of the Movement for Democratic Change (MDC) – will begin talks anytime this week so as to meet the strict time line set by the Southern African Development Community (SADC) mini summit.
The time line in the communiqué issued after the SADC summit says the parties should engage in dialogue with immediate effect within 15 days and not beyond 30 days and that the dialogue should include all outstanding issues.
"After 15 days President Zuma will come here to access progress and if there is no agreement within a month then there will be another summit," MDC-T spokesperson Mr Nelson Chamisa said. "We suspended our disengagement after a persuasive effort by our guarantor, which is SADC.
"We felt obliged, out of respect, to comply with the position of SADC."
Mr Tsvangirai gave Mr Mugabe 30 days to resolve the outstanding issues of their power sharing agreement.
The former opposition leader wants Mr Mugabe to reverse the unilateral
appointments of his cronies to head the central bank, the attorney general’s office and provincial governors.
The party is also demanding an end to politically motivated arrests of its MPs and the ongoing prosecution of its treasurer general Mr Roy Bennett who returns to court on Monday facing banditry charges.
Before the SADC mini summit, Mr Mugabe, who faces severe pressure from Zanu PF hardliners determined to maintain their hold on power argued that he had met his part of the bargain.
He maintained that the only outstanding issues were the targeted sanctions imposed on his family and his inner circle for their involvement in human rights violations before the formation of the unity government in February.
But the SADC communiqué issued after Thursday’s summit attended by leaders from Mozambique, Zambia, Swaziland, DRC and South Africa said "the parties should fully comply with the spirit and latter of the GPA and Sadc summit decisions of 27 January 2009."
Mr Chamisa said their decision to suspend the three week boycott of cabinet and council of ministers meetings showed that they now had faith in the SADC mediation led by Mr Zuma.
Mr Brian Badza, a political science lecturer at the University of Zimbabwe (UZ) said the 30-day time frame was "unrealistically ambitious" considering that the parties were currently "poles apart".
"I don’t see much being achieved during the given time frame because the two parties are poles apart," he said.
"No key issues would be resolved. Only issues of little significance. issues that do not tamper with Zanu PF’s strategic interests would be solved," Mr Badza said.
"Zanu PF hardliners would not agree to anything that would compromise their socio-economic and political interests."
Professor Eldred Masunungure, another UZ lecturer concurred, saying even if Mr Mugabe failed to meet the deadline, the inclusive government will not collapse because the parties have realised that they cannot do without each other.
The Prime Minister’s spokesperson Mr James Maridadi said he was hopeful that Mr Mugabe would have addressed the outstanding issues within the 30 days.
"We are very hopeful," Mr Maridadi said.
"In the event that Mugabe does not comply with the agreement and Zuma’s mediation fails, it would mean the collapse of the government."
An exiled Zimbabwean journalist Ms Gerry Jackson felt that SADC leaders were still not tough enough on the veteran ruler. "It is unclear how it’s possible to read this document (SADC communiqué) as a deadline on Mugabe to implement the GPA within 30 days," she said.
"It would appear to be a document that says nothing more than remove sanctions on Mr Mugabe and his ruling elite and start talking again within 30 days."