With the escalation of diplomatic issues between Qatar and other gulf states (CNN article), Emirates (EK) and Etihad (EY) have suspended, until further notice, all flights to Qatar.
Fly Dubai (FZ), Gulf Air (GF) and airlines from Saudi Arabia have also joined the ban. Expect airlines from Egypt to follow suit since Egypt is also involved in this diplomatic issue.
If you are flying Qatar (QR) though DOH on to one of these Gulf States, make sure to check your itinerary and make alternate travel plans.
Update: The island nation of the Maldives have also cut ties with Qatar. Many people fly Qatar (QR) from Doha to Male (Maldives). If you are on your way to paradise via DOH make sure you change your itinerary!