Update: October 24, 2011
The Home Affordable Refinance Program, also known as HARP, now HARP 2.0, the Obama relief refi, etc has been updated. The HARP program was designed in April 2009 to help underwater homeowners refinance when their existing loan was currently owned by Fannie Mae or Freddie Mac. The program essentially could help homeowners refinance their existing mortgage at the historically low interest rates without being subject to mortgage insurance or loan ineligibility due to the drop in value of their home.
Although the new program details have yet to become available to the general public for an actual refinance at this time there are some key program details that have been released.