The Norwegian Nobel Committee that attributes the prize had a record 241 individuals and organisations on its top secret list, with the name of the laureate to be unveiled at the Nobel Institute in Oslo at 1100am.
While Nobel watchers for weeks have been betting the prestigious award would go to a cyber activist who helped bring about the Arab Spring uprising, Norwegian commercial broadcaster TV2 reported late on Thursday it had reason to believe that Liberian President Ellen Johnson Sirleaf would be getting the call on Friday.
"She is the symbol of the new Africa," said the broadcaster, which in 2009 correctly predicted the surprise win by Barack Obama and last year bet heavily on jailed Chinese dissident Liu Xiaobo, who to Beijing's outrage won the prize.
Sirleaf, whose name had not previously figured high on the list of possible winners, is running for a second term and will face elections on Tuesday.
The head of the Norwegian Nobel Committee, Thorbjørn Jagland, meanwhile would only tell public broadcaster NRK earlier Thursday that he believed this year's pick would be "well-received all over the world."
He said the award would be "very powerful ... but at the same time very unifying."
While the 2011 pick "is not without conflict," he stressed the prize would "not create as strong reactions from a single country as it did last year"with the choice of Liu Xiaobo.
He also played down observers' favourite this year: actors within the ArabSpring uprising, which brought the overthrow of autocratic regimes in Tunisia,Egypt and Libya and rattled the ones in Syria, Yemen and Bahrain.
"There are many other positive developments in the world that we have looked at," he said.
The movement, which began on Facebook, "played a key role in maintaining the direction and non-violent character of the uprisings in Egypt," which led to the ouster of Hosni Mubarak in February after 30 years in power, Kristian Berg Harpviken, the head of the Peace Research Institute of Oslo, said.
Google executive Wael Ghonim, also a central inspiration to the protests on Tahrir Square in Cairo, is another observer favourite, as is Tunisian blogger Lina Ben Mhenni, who chronicled the revolution in her country on the internet.
Among other names that have been circulating are Sima Samar, an Afghan doctor and women's rights activist, and Russian activist Svetlana Gannushkina and her human rights group Memorial.
The winner or winners of the award will receive their diploma, gold medal and prize money of 10 million Swedish kronor ($1.48 million) at a ceremony in Oslo on December 10, the anniversary of the death in 1896 of prize founder Alfred Nobel.