Council on Foreign Relations has a very interesting chart  on who financed the massive amounts of debt that the U.S. government issued in the first half of 2009.– it is divided by “official buyers” who generally are government entities have have motivations other than profit and “economic buyers” who are looking for a return.
The Federal Reserve plans to slow and then stop its purchases by the end of the first quarter of 2010. This raises the question of who will replace this source of demand, and at what price.
This would likely result in higher mortgage costs next year  if the Fed stops buying GSE paper because of reduced liquidity (The article has several other charts which serve to emphasis the Fed’s role in stabilizing the banking system and keeping mortgage rates low).
The point of the Fed’s purchases was to lower mortgage rates during the worst of the housing slump and lower funding costs at the GSEs, which were struggling with skittish investors in the private market. That plan has largely worked; rates for a 30-year fixed-rate loan have fallen to 5.11%, according to Bankrate.com, and GSE debt with five-year maturities traded at 30.5 basis points above Treasuries this week.
But most analysts are predicting those rates will rise by at least 50 basis points before the Fed stops buying and could rise even further afterward. That might not hurt as much on the MBS side, as long as investors have an appetite for mortgages, but could pose problems on the debt side if investors are worried about funding an institution that might not be around a few years down the road.
At the same time, there is discussion of dismantling the GSE’s in favor of a new agency  or restructure into smaller  agencies.
My sense is that we can’t revert to the old Fannie and Freddie because they answered to 2 masters: Taxpayers and Shareholders.
I don’t see how mortgage rates don’t edge up next year. That offsets any hope that housing prices will begin to rise and suggests there are a number of years to go before they do.