I was speaking with a U.S. homeowner recently who handed her keys back to the bank. She bought a house in NY State about 5 years ago, substantially renovated her house, but it was still way underwater today. From what she told me, there are many other homeowners who are still in negative equity in the U.S. And there are a large number of homes still going through the foreclosure process in some states.
One company that has been buying up U.S. homes is Waypoint. Have a look at the Waypoint website to see their rental homes. They list and manage directly, without agents. An interesting story about Waypoint is here. There is consolidation occurring in the buy-to-rent market in the U.S.