Until not so long ago the "multi-cultural" society was in fashion. But nowadays the pendulum has swung the other way and it is in fashion to talk about integration.
The most famous example of integration is probably the American "melting pot". Its succes is based several factors: It begins that people expect that they will have to integrate some the when the move to the USA. They may spend their lives in mono-ethnic communities, like the Chinatowns, but the expectation is still there for the next generation. It helps also that people in the US are highly mobile, so many people will move at some time in their lives to areas where their ethnic group is rare, so that they have to integrate.
It is also interesting to notice the limits of the integration: blacks don't integrate very well. This has to do with discrimination. Not the official kind of discrimination: there were laws that discriminated the Chinese too at some point, yet it didn't hamper their integration. The real difference is that the discrimination of the blacks is rests on stereotypes that nearly everyone shares to some degree.
The US is not the only country that integrated its minorities well. France is another example. They did it by suppressing local languages, like that Breton and German. Yet it worked: for example the Alsace has within a few generations been converted from German speaking to French speaking and there is hardly a complaint. The secret: a sense of equality. One of the ways to achieve this is an educational system that is based on achievement. Everyone who manages to qualify for one of the "grand écoles" is nearly certain of a nice carreer.
France is not the only country that has integrated minorities well. Another example is Greece, that has been quite successful in integrating its Vlach, Slavic and Albanian minorities. Many of those people now feel primarily Greek. Iran is another country that until now has been quite successful, but it is still in an early stage of integration and things may yet go wrong.
On the other hand you have for example Turkey that never has been able to give its Kurds the impression that are equal. I consider it more or less inivitable that some day they will have to give up on Kurdistan and give it independence. England had a similar experience with Ireland a century ago. They mostly succeeded in imposing their language, but they failed on creating equality.
Kosovo and integration
That brings me back to Kosovo and the position of the Serbs there. Serbs are demanding autonomy, while Albanians are refusing it in the name of "integration".
To quote some fragments from a recent article:
"We never have said that we don't support decentralisation. But we have been reserved and we still are, especially regarding the creation of mono-ethnic municipalities … We want to integrate the communities, and the creation of mono-ethnic municipalities is in opposition to this,"
"The process might have its difficulties. I don't know how it is functional for a village located 1km from the centre to be part of another municipality that is, for example, 20km away,"
As I tried to prove above, the crucial part of integration is equality. Separate living or municipalities are not important. The US had its China towns and its Little Italy's but it never doubted that they would integrate one day. Similarly, seperate municipalities will not stop Serbs from Lipljan or Gracanica to integrate.
On the other hand, the ongoing discrimination will hinder integration. So the top priority of Kosovo's government should be to stop that discrimination. A very important aspect of that discrimination is the lack of safety, that - among others - makes it impossible for Serbs to work their lands. The best way to achieve this is to give the Serbs responsibility for their own safety (= police).
One shouldn't expect wonders of course: integration is slow process that takes generations. But one can expect that once the Serbs feel really safe enough to go back to the cities (meaning that not only they will not beaten up, but also that they can rent a house without having burglaries every month) it will speed up.
The above does not apply to the land north of the Ibar. The vicinity to the Serbia will make that the Serbs there feel less need to integrate with the Albanians south of the Ibar. But one should wonder if one should try. Respecting the present ethnic border is the easiest thing to do. And it would invite Serbia to do the same in Presevo.
On final note on the language. I consider it only logical that Kosovo's Serbs will learn the Albanian language at school. Unfortunately the gap between the Gheg and Tosk dialects is an obstacle. The present situation - where Gheg is the spoken language and Tosk the official language - makes it very difficult to teach Albanian to the Serbs. If you teach them the official language they will not be able to use it on the streets and as a consequnece they will find it difficult to remember. But if you teach them Gheg they will still be isolated from the official world.