By Emilio San Pedro
Americas Editor, BBC News
One thing that can certainly be said about Fidel Castro is that he is an incredibly hard act to follow in political terms.
Raul Castro now has to grapple with Cuba's economic problems
He managed after all to survive the attempts of 10 consecutive US administrations to undermine his Communist revolution - not to mention the now legendary countless attempts against his life allegedly orchestrated by the CIA.
But that enmity with the US and his socialist ideals also helped to turn him into a regional and global icon of the oppressed.
Raul Castro has been there with him all along but he lacks his brother's charismatic appeal and is far more of a pragmatist than an idealist.
That could serve him well in his new role as head of state and government of a country that teetered on the edge of economic collapse following the collapse of the Soviet Union in the 1990s.
Cuba managed to survive thanks in large part to a series of incremental economic changes he helped implement that brought the island back from the brink, although only just.
And, in fact, the need to improve the Cuban economy and work on making the country and its ruling Communist Party more efficient were all prominent themes in the speech he made after being selected as president by the National Assembly.
Raul Castro said people had to think more locally and not always look to Havana and the central government for solutions.
Raul Castro's pragmatism could be the tonic Cuba needs after more than 49 years of unbridled idealism
He also spoke of the need to deal with the issue of Cuba's dual currency system, which many Cubans feel favours foreigners and the elite at the expense of workers.
And, as he has on several occasions recently, Raul Castro did what had in the past been considered unthinkable - he questioned the successes of the revolution.
He said it was important to take stock and be prepared to focus not only on the communist government's successes, but also at areas where things had not gone well and improve them.
That pragmatism could be the tonic Cuba needs after more than 49 years of unbridled idealism.
But the unexpected decision to forego naming a younger member of the party in favour of choosing the 77-year-old ideologue, Jose Ramon Machado Ventura, as his first vice-president, makes it clear the changes he plans do not involve doing away with Cuba's socialist ideals or communist political model.
Machado Ventura was one of the original leaders of the revolution
The US government appeared less than impressed with the political change in Cuba, calling it more of the same and no reason to lift Washington's decades-long economic embargo on the island.
But the chairman of the Senate Committee on Foreign Relations, Democratic Senator Joe Biden, said travel restrictions should be lifted and that a mail service should be re-established with the island.
Nevertheless, he also agreed with the government that the embargo should remain in place until Cuba dealt with its human rights problems and released its political prisoners.