MBS

http://www.nytimes.com/2012/02/25/business/homes-arent-selling-but-its-an-apartment-landlords-market.html

Saving this extremely relevant article for a blog post.

Edit 4/15: http://www.nytimes.com/2012/04/03/business/investors-are-looking-to-buy-homes-by-the-thousands.html?&pagewanted=all