Look on Wiki, 95% of the people inside "Kosovo" lands are Albanians.
Anyway, the reason the US and large eastern world leaders said yes to it because they wanted to just throw out land to their neighbors. On the other hand, people in Asia and Europe think differently. For Russia, its USSR collapsed, its bordering countries are all of its old republics. A new republic for Russia could be another block in their trade, as trade is diffucult through those areas. [Taxes and junk, hate for the Soviets back there -- apparently]. So they dun like it, India and China are huge manufacturers, Its easier to sell to one country that confer between prices with a new country in that reigon. Spains a pretty rich country, probably, they just want to keep economy up. After all, in places like Europe trades of power is easy, so giving a new country independence and government could lead to all kinds of junk they don't want. So instead, let it be now. [Since, its pretty stable... For now xP]
Also, the terrirory is not much, so they wouldn't get out of it. Better to stay alive with serbia then to die with the dogs. They have no real need or reason to receive independent land in my thought.
No offence, after all, I'm just not seeing how it'll help anyone.