Mullah Baradar, one of the four top commanders who formed the Taliban in 1994, was released from jail last year by the Pakistan government. He is believed to be the highest ranking Afghan Taliban prisoner freed so far.
The answer is so important because the two sides had already agreed in principle on a framework for two crucial issues: the withdrawal of US troops, and a commitment that Afghan soil would not again be used to launch terrorist attacks against the United States and its allies.
The very fact that the US is talking to the Taliban legitimises their role in Afghanistan's present and future. All of this is worrying for India -- a Taliban government in Afghanistan in the near future will mean a hugely increased leverage for Pakistan in that country.
Senior Taliban leaders said that regional powers including Pakistan had approached them and wanted them to meet the US delegation in Islamabad and also include the Afghan government in the peace process but that the approaches had been rejected.