Actually foreign investors are already started or hunting for buying US properties.
http://www.straitstimes.com/Breaking+News/Asia/Story/STIStory_337862.html
Last quarter one of my uncle sold his investment property (strip mall) in Rancho Cucamonga. The buyer is from Taiwan. He closed the deal in a week with the help of firm in LA and went back to Taiwan. As per him real estate (residential and commercial) prices are very cheap in US and returns are good comparing with Taiwan.
If prices go further down, foreign money flows with no Govt incentives.