I think Kosovo's independence, and its support in the West, is about realpolitik.
I think this is about resolving an issue Milosevic created in the late 1980s. It could have gone another way, but in 1999, with the military occupation of Kosovo, and the reaction of NATO and the US, it couldn't go any other way. That was also about the EU and the USA feeling guilty about looking the other way in the region in the early 1990s and now feeling it has to do something in the region. Maybe it isn't the best solution, to have an independent tiny state, it is 1.9 million Kosovars and 100,000 Serbs, but it is the best solution of not very good solutions.
Kosovo will be under EU control/supervision for a long time. It has no civil society, etc. Perhaps EU presence here is the goal. Smuggling, etc, is a problem here, and perhaps the EU can clean it up, or perhaps not.
It is also about energy, energy markets, and energy transport: where will Russia's southern pipeline run? What about nuclear energy from Bulgaria? If the EU is in control of Kosovo, then maybe it has more influence in this.
Russia wants to say this is about creating instability, but I think this is a thinly veiled threat that Russia won't stand by the EU in other matters (when did the EU have a strong assurance from Russia?).
For more commentary, see
Philip Stephens, "Milosevic was the midwife to Kosovo's nationhood," Financial Times, Friday February 22, 2008, page 9. (Commentary).