I wouldn't hold my breath on that. The list of countries who have not yet recognized Kosovo and -- especially those who have definitely stated that they will never recognize Kosovo independence -- might allow limited airspace use or access from the sea for the specific purpose of assisting Serbia in her defense of Kosovo. Like it or not, NATO is the "occupier" and not the native to that region.
Ukraine is on the fence, Belarus and Romania have said "no way" to recognizing Kosovo, Montenegro has said "not yet" -- but the Montenegrin people have said "no way".
It's not as cut & dried as you might think. They don't want a war, but like it or not, Russia is a lot closer to them than to us -- and they aren't going to shoot down Russian planes over this.
The reason is because in the central geographic part of Romania you have populations that see themselves separate from the central government in Bucharest.
Bokababe, Ronin,
You are living in a dream world. There is no Russian cavalry coming to the rescue. They can do nothing. Russia is not going to violate any sovereign countries airspace or assist, help Serbia retake Kosovo militarily. Russia loves its seat on the U.N. far too much to risk losing it over direct military action.
Russia would be seen as the aggressor in its violation and disregard of sovereign territory. The consequences of such a Russian action would destabilise the region and involve far too many nations. They are hamstrung over Kosovo and are not coming to the rescue. Period. Get back to me and let me know when the first VDV/VTA units start arriving in Serbia.