This is the part I find fascinating about this article.
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Recent market research indicates that up to 40 percent of households surveyed in selected metropolitan areas want to live in walkable urban areas, said Leinberger. The desire is also substantiated by real estate prices for urban residential space, which are 40 to 200 percent higher than in traditional suburban neighborhoods -- this price variation can be found both in cities and small communities equipped with walkable infrastructure, he said.
The result is an oversupply of depreciating suburban housing and a pent-up demand for walkable urban space, which is unlikely to be met for a number of years. That's mainly, according to Leinberger, because the built environment changes very slowly; and also because governmental policies and zoning laws are largely prohibitive to the construction of complicated high-density developments.
But as the market catches up to the demand for more mixed use communities, the United States could see a notable structural transformation in the way its population lives -- Arthur C. Nelson, director of Virginia Tech's Metropolitan Institute, estimates, for example, that half of the real-estate development built by 2025 will not have existed in 2000.
Yet Nelson also estimates that in 2025 there will be a surplus of 22 million large-lot homes that will not be left vacant in a suburban wasteland but instead occupied by lower classes who have been driven out of their once affordable inner-city apartments and houses.
The so-called McMansion, he said, will become the new multi-family home for the poor.
http://www.cnn.com/2008/TECH/06/16/suburb.city/index.html