The charismatic Mr. Garang, leader of the Sudanese People's Liberation Movement, was a hero to millions of people in southern Sudan who saw him as the driving force behind this year's peace agreement that ended more than two decades of civil war.
After Mr. Garang's death was announced Monday, his deputy, Salva Kiir , held a press conference in the Kenyan capital of Nairobi to reassure a grieving Sudan that the SPLM and its army would honor the peace deal.
Mr. Salva Kiir was late Monday appointed as a successor to Mr. Garang.
For many southern Sudanese, Mr. Salva Kiir is more in tune with their hopes for the future than Mr. Garang. That is according to Alfred Taban, editor and publisher of the Khartoum Monitor, an English language daily newspaper.
"It is very good news for southern Sudanese," he said. "The majority of them, perhaps 95 percent of them, want a separate south. Salva Kiir is known to be sympathetic to that view, while John Garang was more popular with the unionists [those who want a unified Sudan]."
The peace deal sealed in January gives southern Sudan nearly half the country's oil revenue and more political representation. It also gives the south the right to secede from the north after a six-year interim period.
It is this last aspect of the deal that worries many in the north, including Sudanese President Omar al-Bashir.
Kenyan General Lazaro Sumbeiywo, chief mediator for the Sudanese peace talks, told VOA that the referendum issue was Mr. Salva Kiir's main point of contention. He wanted the southern Sudanese to decide for themselves whether they wanted to break away from the north, General Sumbeiywo said.
Analyst Taban says Mr. Salva Kiir's style is more collegial, which could be a liability in the often-fractious nature of the SPLM.
"It is definitely going to be a liability on two aspects," he said. "One, many of his southern leaders are likely to challenge him because he is not as autocratic as John Garang. Also, he is going to have problems with northern Sudan because the authorities here in Khartoum want someone who is a unionist like Garang."
Meanwhile, the United States sent two senior envoys to Sudan to talk with officials in Khartoum in a bid to help smooth the transition from Mr. Garang to Mr. Salva Kiir.
Also, delegations from across this region of Africa are expected in the southern Sudanese city of Juba, where Garang is to be buried later this week.