Just read that Norwegian will be launching Copenhagen-Belgrade on the 25th of June 2012. Flights will operate on Mondays and Fridays.
Currently the airline flies to Belgrade from Oslo and Stockholm. This past summer they airline had recorded average of 138 passengers per flight (out of 148 on its B733).
On this route they will compete with the glorious Jat Airways and Wizz Air (to Malmo). Recently Cimber Sterling left Belgrade, according to them it is only a seasonal suspension however I doubt that they will be back.
Other route that will be launched by Norwegian are: Copenhagen-Riga/ Bratislava/ Szczecin. Seasonal routes to Burgas and Marseille will be introduced as well. Additional flights to Berlin will also be added.
Link: (sorry, in Serbian only)