IS IT IN MY BEST INTEREST TO WALK AWAY FROM MY ARIZONA HOME?   
You decide.  Numerous variables are involved but the biggest is probably your assessment of the future of housing pricing.  No one can predict future prices, but the conventional wisdoms says that it is probably not realistic to believe that housing prices will increase by more than 4%-8% per year on average.

This site has a calculator that can help you decide

http://www.payorgo.com/