There has been a fair bit of talk on the notion of megachurches fostering 'racial transcendence' (most recently on http:\\www.onestdv.blogspot.com). Here's my take on the diversity issue as it relates to churches.
Different styles of churches for different sorts of people are very important, in my opinion.People need a church where they can feel as if they are a valued part of the community---a little platoon or company of the body of Christ.People differ a LOT on the expressive style of their worship. Everything from silent and contemplative to exhuberant and 'Spirit-Filled'...people with one style DO NOT feel comfortable when they're in an area dominated by an opposing style. Guess what else, different races have different distributions of preferred worship styles---they differ on everything else in terms of the distribution, why should this surprise anyone? Left to their own devices, the extraverts in a population similar to the US will tend to run roughshod over the introverts as well. Churches have their own personalities, and necessarily so. A number of denominations and churches have made themselves into places where introverts are quite at home, by suppressing the ability of the extraverts to dominate the social scene of the church and by attracting a disproportionate share of introverts relative to the population as a whole. My wife, for instance, absolutely can't stand the Pentecostal style of worship, whereas I'm indifferent to mildly friendly to it. Neither of us are at all tolerant of the notion that all cultures are of equal value, excepting White American and European culture, which is evil. Churches are frankly one of the last bastions of free association in the Western World. I get very angry when people try to browbeat churches into 'integrating'. My take is that good churches are open to whoever has a desire to go, and if they want to become part of the community, they'll stay. To go out of one's way to bring 'diversity' to a particular church absent a clear calling from God is, IMO, wrong.