Impact of downpayment requirements in QRM proposal

The proposed definition of qualified residential mortgages (QRM) that would be exempt from risk retention requirements is troubling to a lot of housing organizations and advocates.  Have you been following this?  Any thoughts on what the right approach is?

It's especially troubling since it is doubtful that the QRM definition will only affect risk retention.  Is seems likely to be adopted in other venues to differentiate between good and bad mortgages -- and lead to perfectly sustainable loans being shut out.

In particular, a 20% downpayment just doesn't seem realistic, especially since it would often take more than 10 years for a family with median income have enough savings to put 20% down on a median-priced home.  (See the tables in http://www.mbaa.org/files/Advocacy/2011/RiskRetentionPresentation.pdf)

For those interested in making official comments, the comment period lasts until August 1.  A link to the full (long) rule and where to make comments is here: http://www.sec.gov/news/press/2011/2011-121.htm