Both the Sudanese government and the Sudan People's Liberation Movement/Army (SPLM/A) have said that once a peace agreement has been signed, the return of the country's refugees and internally displaced to their homes will be a key priority.
Both sides are keen to see people move freely after 36 years of conflict out of 47 since independence.
But for the local authorities, donors, UN and aid agencies grappling with the prospect of 570,000 Sudanese refugees, and between 3 million and 4 million displaced returning home en masse, the challenges ahead are staggering.
With no reliable population statistics available for Sudan as a whole, and certainly no accurate statistics on the numbers of internally displaced persons (IDPs), or whether and when they may choose to return, much of the necessary planning is based on assumptions.
Even the term IDP is misleading as a coverall for Sudan's displaced southerners, many of whom fled for their lives from conflict, while many others - especially those in and around the capital, Khartoum - are economic migrants.
Nevertheless, agencies and NGOs are trying to prepare themselves, and some donors are granting project funding for areas in advance of returnees moving there.
But everyone involved agrees that the uncertainties are huge. "No one knows at all how many will return home," Stephen Houston, a senior IDP adviser in the office of the UN humanitarian coordinator in Khartoum, told IRIN.
The only certainty is that if people do move quickly, they will experience tremendous hardship as they walk for days across a country the size of Kenya, Tanzania, Uganda, Burundi and Rwanda combined. With practically no roads, health care, sanitation facilities or infrastructure of any kind to welcome them, they will be vulnerable to hunger and outbreaks of disease both en route and when they arrive.
Keeping their deaths to a minimum is one of the key challenges facing the international community.
THE POLITICS OF RETURNING HOME
"People are going to be induced to move for political reasons," Houston told IRIN.
Being able to return 'home' will clearly send a positive message both home and abroad about a new, unified, peaceful Sudan. But it is clear that the movement of hundreds of thousands of people into southern Sudan before a referendum is held on self-determination will also have huge political consequences.
On top of this, elections will be held during the six-year interim period, as well as a population census after three years, which will determine southerners' access to various sources of national funding and services.
It is considered "very important" to have as many southerners as possible physically in the south before the census, according to Luka Deng, the executive director of the New Sudan Centre for Research, Statistics and Evaluation.
"It is very important, because of the elections during the interim period, that these people are transported back to their homes so the results will be credible," Samson Kwaje, the SPLM/A spokesman told IRIN.
Muhammad Ahmad Dirdeiry, Sudan's deputy ambassador to Kenya, agreed that within three years of signing a peace agreement the vast majority of the displaced should go home. "Definitely by then we would like to see them resettled," he said. "There is the political timetable of the referendum and elections. We want them to move well ahead of the schedule," he said.
Regional analysts argue that despite losing a cheap source of labour, not having up to two million southerners living in slum areas around the capital - jails are reportedly full of poor southern women who have been caught brewing alcohol - might also be a welcome peace dividend for Khartoum.
The governments of neighbouring Kenya, Uganda and Ethiopia, which have been hosting large Sudanese refugee populations for years, may also be keen to see them return home.
Trying to ensure that the movement of Sudan's refugees and displaced is entirely voluntary, and that humanitarian assistance is not furthering the political agendas of either the Sudanese government, the SPLM/A, or the governments of neighbouring states will remain a key challenge.
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