The Norwegian Nobel Committee that awards the prize had 231 individuals and organizations on its top-secret list, with the laureate to be revealed in Oslo at 11:00am (0900 GMT).
The field of possible winners has long appeared wide open, but by late Thursday Europe had rushed to the forefront of speculation.
The usually well-informed public broadcaster NRK suggested on the eve of the big announcement that the committee this year appeared set to finally hand the prize to the EU, 60 years after the birth of its predecessor, the European Coal and Steel Community, which helped bring peace and stability to a continent freshly ripped apart by war.
The broadcaster also cited the continued struggle for civil rights in former communist Eastern Europe and Mexican Bishop Raul Vera Lopez as top picks, and said it had reason to believe there would be only one laureate this year.
Last year's prize was split between Liberian President Ellen Johnson Sirleaf, her compatriot "peace warrior" Leymah Gbowee and Yemen's Arab Spring activist Tawakkul Karman.
Nobel Committee president Thorbjørn Jagland was as usual vague about who would receive this year's honour, telling the Aftenposten daily only that the five-member jury "made a unanimous decision and it was not especially difficult to reach."
Commercial broadcaster TV2's list of likely picks, also often insightful, was meanwhile topped by American political science professor Gene Sharp for his theories on non-violent struggle that have inspired popular uprisings around the world, including the Arab Spring.
The only name the two broadcasters had in common was surprisingly the EU -- membership of which Nobel Peace Prize host country Norway has twice rejected, in 1972 and 1994.
"The European Union is in the middle of one of its worst crises, but perhaps it is precisely now the peace and stabilisation project deserves a hand from the 'no' country Norway?" NRK said.
Former German chancellor Helmut Kohl, a key architect of a united Europe, has been mentioned by other observers as a possible laureate as well.
Committee president Jagland is also the secretary general of the Council of Europe and a fervent supporter of the 27-nation bloc, but recent polls show nearly three-quarters of Norwegians are opposed to their country joining the EU.
If the Nobel winds blow towards eastern Europe this year, prize watchers suggest that Belarus human rights activist Ales Belyatsky, sentenced to four and a half years in a prison camp after what the EU decried as a "political trial," would be a likely pick.
A number of activists from Russia also figure among the most widely predicted to pocket the prize, including 85-year-old Lyudmila Alekseyeva, who has spent the past half-century defending human rights in the Soviet Union and in Russia.
Human rights group Memorial and one of its key figures, Svetlana Gannushkina, were also mentioned among possible Russian winners, as was Moscow Echo Radio, described by some as the last bastion of free media in the country, and its chief editor Alexei Venediktov.
Twenty years after the Nobel Peace Prize last went to Latin America, when Guatamalan Rigoberta Menchu took the 1992 honour, NRK also hinted the nod could go to Mexican Bishop Lopez, who has defended the most vulnerable in a Mexico caught in a bloody struggle between drug cartels and the military.
The winner or winners will receive the prize, consisting of a Nobel diploma, a gold medal and 8.0 million Swedish kronor ($1.2 million), at a ceremony in Oslo on December 10th, the anniversary of Swedish industrialist and prize creator Alfred Nobel's death.