The ghost towns of the housing bust are places that lack transportation options, that aren't walkable. The average family spends 52 cents of every dollar they earn on housing and transportation combined, so the biggest opportunity in development is around transportation. - Shawn Donovan, US Secretary of Housing and Urban Development
This is a telling quote taken from this recent Business Week article. Just from an informal survey of my peers, people are looking for places where they can walk, bike or take transit but unfortunately not as many of those exist as the demand would like. That makes the real estate in these locations a bit more expensive than others.