By Peter Biles
BBC Southern Africa correspondent
Morgan Tsvangirai's return to Zimbabwe signals a new phase in the efforts to end the country's political impasse.
The next few days may shed some light on what to expect in 2009, but Zimbabweans know better than to hold their breath.
The national executive of Mr Tsvangirai's Movement for Democratic Change (MDC) is holding a critical meeting this weekend.
President Kgalema Motlanthe of South Africa is leading a Southern African Development Community (SADC) delegation to Harare on Monday for a resumption of the inter-party dialogue, and parliament is set to reconvene on Tuesday.
After weeks of inactivity over the festive season, there is suddenly a new sense of urgency about the political deadlock and the worsening humanitarian crisis, with the cholera epidemic still not under control.
However, Mr Tsvangirai was relaxed when we met in Johannesburg on Thursday.
He admitted that his return home after more than two months away was "long overdue".
He has spent much of that time in neighbouring Botswana, but categorically denies allegations that the MDC has been using Botswana - or any other country - as a base for military training.
Mr Tsvangirai says he was only issued with a new Zimbabwean passport on Christmas Day, after a six-month wait.
In his BBC interview, Mr Tsvangirai - still prime minister-designate - insisted that he remained committed to last September's power-sharing agreement and to the formation of a new inclusive government, but he says he lacks "a willing partner".
"Robert Mugabe is part of the solution, but he is also part of the problem. As far as we are concerned, we can work with Zanu-PF, but the difficulty in implementing the agreement is Robert Mugabe 'the person'. I am hoping that Zanu-PF will appreciate that for the country to move forward, Mr Mugabe has become a liability to both Zanu-PF and to the country," said Mr Tsvangirai.
MDC leaders face a serious dilemma as they meet.
The party can join an inclusive government, subject to the resolution of a number of outstanding issues including the management of security departments and the allocation of ministries.
Cholera has added to the suffering of ordinary Zimbabweans
The risk here is that the MDC's authority may be significantly weakened in the process, as Mr Mugabe rides roughshod over the spirit of the September 2008 agreement, and continues to control many levers of power.
Alternatively, the MDC can adopt a hard-line approach and refuse to form a government.
This could, in turn, kill off the idea of power-sharing once and for all. President Mugabe would almost certainly proceed to form a government unilaterally.
He has already hinted that this is an option, and has begun clearing the decks by firing ministers who lost their parliamentary seats in last year's elections.
No 'Plan B'
Hence the new mission to Zimbabwe by SADC which would clearly like to be able to report some progress at the forthcoming African Union summit in Addis Ababa.
South Africa - the current chair of SADC - remains focused on trying to secure an agreement on a new government, not least because there appears to be no "Plan B".
"We cannot see any route that has immediate prospects for success that bypasses the stage of some variant of an inclusive government in Zimbabwe," said Ayanda Ntsaluba, the director general of the department of foreign affairs, at a briefing in Pretoria this week.
Last week, ANC leader Jacob Zuma called on Zimbabweans to "walk the extra mile to find an urgent solution".
He underscored the fact that Zimbabwe is very much a domestic issue for South Africa.
"What the Zimbabwean leadership must remember and understand is that this situation is affecting us very directly as South Africans - socially, economically and in various other ways."
The constitution is to be changed to let Morgan Tsvangirai become prime minister
Against the background of the continuing political uncertainty, there are fresh warnings of the human suffering that Zimbabweans face.
International aid agency Oxfam says Zimbabwe has entered its peak hunger period with more than half the population now dependent on food aid.
It says 5.1 million people are relying on food hand-outs, and the likelihood is that this year's harvest will be even worse than last year's.
At the same time, Save The Children has warned that the real cholera death toll is being hidden by a lack of awareness and under-reporting of under-five deaths from the disease.
According to official figures, more than 2,000 people have died from cholera, but the agency suspects that many babies and young children who are among the most vulnerable, are dying without the disease being identified or recorded.
No less serious is the two-week delay in the opening of schools.
Attendance had fallen to 20% by the end of last year, with teachers unpaid and unable to get to schools.
Zimbabwean writer Cathy Buckle, who publishes a weekly online letter to family and friends, says the failure of schools to reopen on time is "culling yet more precious days from our children's education".
"All these apparently little things are having a dramatic impact on our lives in Zimbabwe. Our children and our country will pay a heavy price in the years to come."