More on possible successors:
http://news.bbc.co.uk/2/hi/middle_east/1362216.stm
Summary of contenders from the Beebs article:
AHMED QUREI ('TUNISIAN')
Ahmed Qurei
Better known as Abu Ala, Mr Qurei is the Palestinian prime minister and a figure closely involved in the secret negotiations which led to the Oslo peace agreement with Israel in 1993.
Born in Jerusalem in 1937, Mr Qurei rose to prominence in the PLO in the mid-1970s, and was close to Yasser Arafat in Lebanon and Tunis, before returning to Gaza with the PLO leader in 1994.
After taking over as the Palestinians' second prime minister in September 2003, Mr Qurei exhibited an independence which sat uneasily with Mr Arafat's autocratic style.
He threatened to resign several times over Mr Arafat's failure to give him sufficient powers, but was always persuaded to stay.
Profile: Ahmed Qurei
MAHMOUD ABBAS ('TUNISIAN')
Mahmoud Abbas
Mahmoud Abbas, also known as Abu Mazen, has taken over from Yasser Arafat as chairman of the PLO.
Mr Abbas had long been Mr Arafat's number two in the PLO. Co-founder of the Fatah movement, he is another moderate who has frequently negotiated with the Israelis.
In early 2003, he was appointed by Mr Arafat as the Palestinians' first ever prime minister. The US, Israel and the European Union had insisted the Palestinian leader hand most of his powers over to another leader.
Abu Mazen's leadership was meant to open a new chapter in Israeli-Palestinian relations in which the peace plan known as the roadmap was meant to lead both sides towards resolution. He resigned after four months after losing a power struggle with Mr Arafat.
He is an outspoken critic of the violence that has been used in the current four-year-old Palestinian intifada and tried to get Islamic militants to end attacks on Israel.
Profile: Mahmoud Abbas
FAROUK KADDOUMI ('TUNISIAN')
Farouk Kaddoumi
Farouk Kaddoumi's appointment as head of Mr Arafat's political organisation, Fatah, was not widely foreseen.
Mr Kaddoumi, who is seen as a hardliner, was among those who founded the Fatah movement in 1965.
To show his opposition to the Oslo peace accord, he stayed behind in Tunis when his colleagues returned to Gaza and the West Bank to set up the PA a decade ago.
Since taking the reins at Fatah, Mr Kaddoumi has said he is open to peace negotiations with Israel - but is also ready to pursue armed struggle if they fail.
A potential contender for the post of PLO chief, he is said to have voted for Mr Abbas. Observers suggest that there could still be a power struggle with Mr Abbas. It remains unclear if he will leave his home in Tunisia for the Palestinian territories.
NABIL SHAATH ('TUNISIAN')
Nabil Shaath
Nabil Shaath had long been one of Mr Arafat's closest advisers and has been an important negotiator in Palestinian-Israeli talks.
Most recently, he played the role of ambassador to the outside world for Mr Arafat, who was under virtual house arrest in Ramallah before his death.
The former businessman who holds the post of foreign minister has a reputation of being a moderate.
YASSER ABED RABBO ('TUNISIAN')
Formerly a member of one of the left-wing factions, Yasser Abed Rabbo is now a senior PLO official. He is a former Palestinian Authority minister of information and culture.
Last year, Mr Abed Rabbo produced the Geneva Accord along with Yossi Beilin, a one-time Israeli justice minister and one of the main architects of the Oslo peace accord. The plan, an alternative to the US-backed roadmap, sought to define a "final status" solution based on a division close to that of the pre-1967 borders.
Earlier this year, Mr Abed Rabbo was among 60 leading Palestinian intellectuals and officials who signed a prominent advertisement urging Palestinian militants not to carry out suicide bombings against Israelis.
MOHAMMED DAHLAN ('INSIDER')
Mohammed Dahlan
Mohammed Dahlan is the former security chief in Gaza. As such, he has considerable experience of dealing face to face with the Israelis. He has also enjoyed the confidence of the United States.
Mr Dahlan is without an official post but retains influence in the Gaza Strip. He has been courted by international mediators as someone who could instil order there after a planned Israeli pullout next year.
His relations with Israel and the US have been viewed with deep suspicion by some Palestinians.
Profile: Mohammed Dahlan
JIBRIL RAJOUB ('INSIDER')
Jibril Rajoub
Jibril Rajoub is the former security chief of the West Bank, where he had built up an independent power base.
Like Mr Dahlan, he had fallen in and out of favour with Mr Arafat. But he is still influential and has considerable experience of dealing with the Israelis. Also, like Mr Dahlan, he is considered to be a pragmatist.
He speaks fluent Hebrew and English and is seen as acceptable in Washington and Israel. This, however, has affected his grassroots support.
Profile: Jibril Rajoub
MARWAN BARGHOUTI ('INSIDER')
He was the head of Fatah in the West Bank. Many believe him to be the most popular Palestinian politician after Mr Arafat.
Barghouti is currently in an Israeli jail serving five consecutive life sentences.
He was a strong backer of the Oslo peace accords and opposed attacks on Israeli civilians inside Israel. After the start of the current intifada in 2000, he became more militant.
He now backs Mr Sharon's Gaza disengagement plan, describing it as a great achievement of the intifada.
Profile: Marwan Barghouti
(Much more detailed profiles on the BBC site)