Multiculturalism.
If there's a more loaded and abused buzzword out there today, I know it not. Ranks right up there with some of George Bush's meaningless gems like "freedom is on the march." At its root, all this word means is "the belief in many cultures". That can mean all kinds of things, depending on who's saying it
For example, my ex took a college class for her psychology degree called Multicultural Psychology. She and I thought it would explore the way different cultures handle common mental disorders, and the effect cultural upbringing has on the development of the brain. It ended up being mostly a roomful of loud Latino girls from the Bronx getting a chance to talk about the immigrant experience and the social problems in their community, and bitch about how misunderstood they are by anglo-American culture.

8)
There's a place for that, and it ain't a class offered by a reputable college psych department. As an exchange student fresh from Taiwan with no experience in the US, the class was one big shrug to her.
I interpret multiculturalism to mean believing that no culture is inherently better or more worthy or "right" than any other. And this I agree with. We're all beautiful beings; we're all dumb hairless monkeys too.
But seriously, people of different cultures living side by side is only problematic when key resources needed for survival are in short supply, whereby people will break off into groups like a puddle of mercury hit with a hammer, each group coming up with far-fetched reasons why their people are more deserving of the resource than others. Then the violence starts. Show me a place where pluralism isn't working, and I'll show you a place where not everybody has everything they need.
I'm taking a class at a college that's extremely diverse (most student come from NYC, so that figures). All the different ethnic, national, racial, and religious groups seem to get along fine, and even *gasp* intermingle!
As pope John Paul put it, you want peace, work for justice.
Not homogeny.