It had not occurred to me before, but for anyone interested in the leadership of the Taliban in Afghanistan - and that includes the Haqqani faction as well as the Quetta Shura - then the list of banned individuals posted by the United Nations is a good starting point. While the actual composition of the Quetta Shura of the Taliban (QST) appears to be unknown, most of them are likely to appear on this list.
Amongst those on the list of 144 Taliban leaders are, for example, Ubaidullah Akhund, formerly the Taliban minister of defence, who is described as "one of the deputies of Mullah Omar, and a member of the Taliban's leadership, in charge of military operations". Sayed Esmatullah Asem is named as a member of the Taliban's leadership as of May 2007, and a member of the Taliban council of Peshawar. Abdul Ghani, aka Mullah Barodar, the Taliban's former deputy defence minister, is described thus: "Belongs to Popalzai tribe. Senior Taliban military commander and member of Taliban "Quetta Council" as of May 2007. Believed to be in the Afghanistan/Pakistan border area."
The list itself is clearly important to the QST. They have made it clear that they want to see it lifted as a precondition for negotiations with the Karzai government and the United States. At the moment, QST members who want to travel out of Afghanistan or Pakistan do so on Pakistani passports issued through the ISI. This is what happened, for example, when representatives of the QST travelled to Saudi Arabia for talks last year.
Earlier today, Kai Eide, the outgoing UN representative in Afghanistan, told the New York Times that some of the Afghans should be removed from the UN list. "If you want relevant results, then you have to talk to the relevant person in authority," Eide said. "The time has come to do it," he said, adding that the US should also carry out a review of the detainees held at the Bagram American military prison to see if any of them could be released.
The UN list itself can be found here. Only one person, General Rahmatullah Safi, the Taliban's former representative in Europe, has ever been removed from the list, in 2005. He died the following year.
Last week, according to the NYT, US special envoy to Afghanistan and Pakistan, Richard Holbrooke, said “Some of the people on the list are dead, some shouldn’t be on the list and some are among the most dangerous people in the world. I would be all in favor of looking at the list on a case-by-case basis to see if there are people on the list who are on the list by mistake and should be removed, or in fact are dead”.
All UN member states are required to a) freeze funds and any other financial assets of anyone on the list; b) Prevent the entry into or the transit through their territories; c) Prevent the direct or indirect supply, sale, or transfer of arms and related material, to the individuals, groups, undertakings and entities placed on the Consolidated List.
Update: On Wednesday, the day before the London Conference, the UN lifted sanctions on five former Taliban officials, including former foreign minister Wakil Ahmad Muttawakil. The four others were the Taliban's deputy commerce minister, Faizl Mohammed Faizan; Abdul Hakim Monib, the deputy minister of frontier affairs who later renounced the Taliban and became a provincial governor; Mohammad Musa Hottak, the deputy planning minister who was later elected to parliament; and a former press officer, Shams-ul Safa Aminzai.