The opposition, slammed Chiwenga's appointment, saying that it "brings full circle a sinister scheme by the military to push out former president Robert Mugabe for selfish reasons".
A priest who brokered Mugabe's exit speculates that Grace will be prosecuted after he dies.
It will be the first time in many years.
He reportedly flew to Singapore for medical checks.
Robert Mugabe's allies have been dropped from the cabinet.
As the euphoria over the demise of the dictator subsides, Zimbabweans will realise the military are as much in charge under the new boss as under the old.
“When he finished his signature his face just glowed, no weeping unless there were angels weeping somewhere".
Zimbabwe's army’s action was the culmination of months of planning that stretched from Harare to Johannesburg to Beijing.
This is a key decision as the military has sought to show that its actions were not a coup.
"If there is going to be a change, it will be by a long shot."
"The people have spoken. The voice of the people is the voice of God,” he told thousands of supporters on Wednesday.
Zuma was scheduled to travel to Zimbabwe on Wednesday to assess the situation there.
The 75-year-old was one of Robert Mugabe’s most trusted lieutenants, having been at his side in prison, during wartime and then in government.
The 93-year-old president stepped down on Tuesday.
Zanu-PF hopes to impeach Mugabe on Tuesday, but it will need opposition support.
"ZDF rightly intervened with corrective measures in the best interest of the president and the nation at large"
His best option will be to grab those two suitcases, make a hasty exit and move in next door to Bob and Grace in Dubai.
Former South African President Thabo Mbeki's recall created both a constitutional crisis and an interregnum.
Mugabe stunned Zimbabweans in a rambling late night Sunday television address by avoiding any mention of resignation.
Zimbabwe president Robert Mugabe made no mention of resignation in a television address, defying his own ZANU-PF party which had sacked him hours earlier.