Apparently what's left of the Taliban is concentrated mostly in the southeast, especially in Kandahar province. There are several reasons for this, not least the proximity to Pakistan's Northwest Frontier region, still only lightly controlled by the Pakistani government. But a major contributing factor is the inability of the Afghan central government to bring the corrupt provincial governor, Gul Agha Shirzai, fully under control. The Taliban has been heavily working its claims to be able to provide "good government" based on Islamic traditions against the corrupt secularists, who are supported by infidels. It helps to have a corrupt governor in office.
The Afghan government has been having a fair amount of success disarming the warlords and is slowly integrating their militias into the new regular army. Warlords who cooperate are being given plumb assignments -- though often posts with little real power. For example, Abdul Rashed Dorstam, a leader of the northern Uzbeki community, has recently been made Chief of Staff to Army Headquarters, while still being permitted to remain as head of his old faction, now converted into a proper political party.
The central government has become increasingly concerned about the extent of Iranian intelligence penetration of the southwestern region. During the Taliban years, this area was the scene of an unofficial war between Iran and the Islamists movement, since the Shia leadership in Iran was concerned about keeping the Taliban out.
Armed Taliban are operating in groups of one to three dozen men. Traveling in pickup trucks, they try to attack police stations, or ambush army patrols. This has become increasingly dangerous, because more Afghan police and soldiers have good radios, and can immediately call for reinforcements. These often include American helicopters and aircraft (A-10s, UAVs, fighter-bombers). If the Taliban cannot get far enough away to fade into the woodwork, the American aircraft will find them, and coordinate air and ground attacks. This often results in the surviving Taliban scattering into the hills or villages, and escaping. However, at that stage, another Taliban marauder group is out of action until its members can get back together and maybe try again.