President Obama released a housing proposal Wednesday that aims to help more homeowners refinance their mortgages. The plan is the latest effort by the administration to help homeowners. It would allow those who are current on their mortgages to refinance at lower rates, even if they owe more than their home is worth. The administration says the effort could save millions of homeowners an average of $3,000. But past housing efforts have not lived up to billing, and this one faces its first obstacle on Capitol Hill.