NPR says walking away from a home need not be . The station’s reporters found a web site called You Walk Away that “empowers homeowners who purchased their homes at the peak of the real estate market to take control of their financial future.” Which is not-so-subtle code for reneging on your mortgage.
The site has an interactive calculator that helps you figure out whether you should walk or not. Seeing how their business is helping people walk away, I’m guessing the calculator is biased. Still, it may be worth looking into for some readers.