Lucia,
My read from several articles did raise the same question, in that most articles do describe Treasuries actions as "Guidance". However, these are reported as rules to become effective 4/5/2010. Beginning next week Treasury has stated they will publish results of banks not following the program guidance. I know that few of us think that "shaming" banks into action is likely to have material impact. While none of the articles discussed penalties, I presume that at a minimum the financial incentives from Treasury would be withheld. Some high paid official somewhere figured out that short sales actually cost less than proceeding through foreclosure with legal fees and another 4-12 months of holding the property without recieving payments. While not a cure-all, and like many government programs without real teeth, it is at least a public move to encourage short sales. As to banks cooperation for now, or compliance after 4/2/2010, or Treasury Dept. enforcement we will have to see.