The only way housing could conceivably fall (without intense depression-level pain) is if the entire rest of the economy inflated such that housing was reasonable. Everyone would be making six figures, a gallon of gas would be $6, a loaf of bread over $10, but housing would be reasonable again.
Depends on how financially solvent you are to manage the upkeep (Principle, interest, prop tax, insurance) if your wages drop or you lose your job.
http://blog.altosresearch.com/how-sustainable-are-the-exorbi...
More accurately we could say that housing will never be allowed to fall. The entire economy will be sacrificed at the altar of home values. Homeowners vote more than non-homeowners, and so much investment capital is tied up in housing that a major fall in home values would destroy the financial system.