Eugene England, in his book, Why the Church is as True as the Gospel, points out that the geographic organization of the Church puts us in contact with people we might not otherwise choose to serve or choose to serve with, and that this stretches and develops us. This practical aspect of the Church can transform us as much as the doctrinal beliefs can.
However, as the country has seen formal segregation change to informal segregation, with minorities concentrated in dense urban areas and the more affluent occuping the suburbs, it seems the Church feels the effects of this, and it lessens the potential England discusses. I lived just outside Baltimore, Maryland, for a couple of years, and the demographics of our suburban ward were very different from the demographics of the downtown Baltimore wards -- and the problems we had to solve were also very different. The impact of this kind of separation on the Church is likely strongest where there is a high concentration of Church members (and each ward is therefore geographically smaller). For example, my parents live in Lindon, Utah (about 20 minutes north of BYU). The few neighborhoods that comprise their ward are very homogenous, with a few minor exceptions as children inherit from their parents.
England's point still holds true to some extent. Unlike other churches, we generally don't choose the congregation we prefer to go to. (I say “generally,” but when we moved to Minnesota, the ward was a factor in our decision of which area of the city to move to.) This ensures that there will at least be some diversity in our approaches to the gospel. But we may miss out on other productive tensions as our wards reflect the relative homegeneity of the geographical area in which we live.
Should the Church try to find ways to mitigate this? Is the Church trying to do so? If so, how? What might be some good suggestions? Do we have an additional individual responsibility to step out of our comfort zone to serve those who are different from us?