A meeting between ethnic Hazara elders and local Taliban commanders was held as the Hazaras want protection from IS. The Hazaras are a Shi'ite minority killed off in great number by the Taliban and have been enemies for some time but the Hazara feel that IS is more of an immediate threat and this threat comes in the form of masked men calling themselves "Daish," which is the regional term for IS, who've already kidnapped many Hazaras. This request was agreed to by the Taliban commanders. The growing fear isn't really one of military fear but of that the global "brand" of IS would attract many members of the battle weary Taliban who've become fractured. The fear is also that of religious minority Shi'ite, such as the Hazaras, as IS is extremely, and violently, anti Shi'ite.
Despite not having an official territory hold in Afghanistan and no systemic support many are still worried as Taliban fighters have already reported armed encounters against IS fighters. There are reports that as many as 6 provinces have IS members operating in them. This growing number and string of recent attacks breeds concern amongst the Aghani Government, Taliban, and the Hazaras, though no one has claimed these attacks many blame IS.
The combination of such old enemies shows how concerned they really are with the growing IS threat but also spreads some level of alarm at how far the hand of IS has been reaching. I don't think it will be long until the Taliban and IS are on a full scale war with each other such as has been seen in Iraq. I personally hope that IS gets extinguished by the Taliban and those who wish to see them gone.