According to a recent study by Lender Processing Services, foreclosure starts continue to be dominated by GSEs (Government Sponsored Enterprises). However, GNMA (or Ginnie Mae, Government National Mortgage Association) activity is almost negligible. GNMA is a government-owned agency which acts as a secondary market conduit for FHA and VA loans.
GSEs are also pursuing foreclosures more aggressively than other types of investors.
From the LPS study for September 2010:
The increase in foreclosure inventory has accelerated dramatically over the last 4 months for agency prime product as GSEs have ramped up foreclosure starts.
The average number of days delinquent for loans in foreclosure has increased from 251 to 484 days since January 2008 and is still on the rise.
You can read the full study here.