PGT
Pegasus are just taking over from Atlasjet who operated last summer (previously operated by Onur for a couple of seasons, before that Bosphorous European - remember them?!). So it isn't really a new flight.
Turkey is indeed all the rage this summer it seems, Onur are returning flying on Mondays to Bodrum, and Thursdays to Antalya and Dalaman. Sun Express are adding Izmir on Tuesdays and Saturdays.
THY is upgrading to a daily A321.
This is the first time Pegasus have operated to STN, and is the first time that they have ever operated scheduled flights.