Kenyatta is facing trial at the International Criminal Court on charges of crimes against humanity in the deaths of 1,200 people after the bitterly disputed 2007 presidential poll in which his rival, Prime Minister Raila Odinga, was among the losers.
Kenyatta, son of the late Jomo Kenyatta, a towering figure in Africa's post-colonial politics, was declared the winner in the closely fought poll March 4 election.
Uhuru Kenyatta took 50.07 percent of the 12.3 million votes cast, just enough to avoid a runoff against Odinga, who had 43.31 percent of the vote.
Amid growing concerns about the validity of the ballot, with an unusually high 10 percent of votes declared invalid, and the shortcomings and breakdowns in the computerized tallying system intended to avoid the vote-rigging accusations of 2007, Odinga branded the electoral process "tainted."
He said he'll challenge the result in Kenya's Supreme Court and called on his followers to remain calm.
Despite widespread fears of violence, the election produced no major eruption of the fierce tribal rivalries that took Kenya to the brink of civil war in three months of bloodshed triggered by the December 2007 poll.
However, it was clear the voting left the country still bitterly divided, with the narrowness of Kenyatta's victory feeding his opponents' anger.
Much will depend on what happens in the next few weeks, as Odinga's challenge makes its way through the courts.
Observers expect legal challenges after myriad failures in the systems established by Kenya's electoral commission following the 2007 affair.
Whatever election-related developments occur, Kenya's new leaders have other battles on their hands.
Kenyatta's victory, by a mere few thousands votes, is likely to come under intense scrutiny since the new head of state of one of Africa's foremost countries, and his running mate William Ruto, will have to go before the ICC in The Hague to answer charges they directed, incited and provided weapons for the savage deaths of their countrymen in the 2008 bloodbath.
Ruto's trial is scheduled for April; Kenyatta's for July.
Africa Intelligence, a Paris website, warned, "This election victory is like a ticking time bomb."
It went so far as to say that on top of the traditional tribal divisions that have marred Kenya politics since independence from Britain in 1963, the tactical alliance between Kenyatta's Kikuyu and Ruto's Kalenjin could fall apart if one of the partners is convicted in The Hague.
There's a widespread expectation Kenyans will show restraint because of the 2008 atrocities but, with Kenyatta's trial likely to fan political and tribal rivalries, Africa Intelligence noted, "This election victory will do nothing to erase the various major land disputes between the rival communities."
These quarrels have pitted rival tribes against each other, particularly in the fertile Rift Valley, since independence and were heightened by the 2008 bloodletting.
Kenya also faces a wider, diplomatic problem now that it's elected as president a scion of the nation's leading political dynasty who may be convicted of mass murder and wind up serving a life sentence in a foreign prison.
British international affairs specialist Simon Tisdall commented that Kenyatta's victory, "if confirmed, would lead the international community into dangerously unfamiliar territory, with possibly far-reach deleterious consequences for U.S. and British relations with Kenya, U.N. operations and the struggle against al-Qaida-style Islamist extremism."
The spectacle of Kenya's head of state put behind bars by the ICC "would inevitably be portrayed as partisan, biased and part of the post-colonial West's alleged wider vendetta against black Africa," Tisdall wrote in The Guardian newspaper.
"Worse, it would compromise the arguably much stronger but so far stalemated ICC genocide and war crimes case against Omar al-Bashir, president of Sudan, and possible future cases involving, for example, Syria's Bashar Assad.
"The U.S., Britain and leading figures including Kofi Annan the former U.N. secretary-general, have already made clear, in a roundabout way, that Kenyatta's victory would not be welcome," Tisdall observed.
"Britain has indicated officials will avoid any but essential contact with him. If London sticks to this approach, a diplomatic rift may be inevitable."