Are there any connections to Pristina via Nis?  I have found buses from Belgrade, but I'm in Sofia and it seems geographically logical to go from Nis without going north before turning around to go back south.  Thank you. 

Minivan Nish - Prishtina, every day, dep. 04:00h and 14:00h from Rodic supermarket in front of main bus station in Nish. 500 dinars per person (~6 euros).

Contact: +381 (0)64 12 321 01  (Boyan)

Just call to reserve your place 1 day in advance (recommendable, but not always needed).

Buses do not go from Nish to Prishtina, but to Kosovska Mitrovica, there's one per day ~10:20h, and goes all the way around small towns so ride takes ~5 hours, and still in K.Mitrovica, you have to cross into southern part and take bus to Prishtina.

Nish to Prishtina is a common question from many guests in this www.hostelnis.com hostel where I used to work, and general solution is this minivan, as its cheap, the fastest and very reliable.

happy travels.

Hvala very very much.  Sorry for the late response.