Today the Federal Reserve announced it will extend purchase of mortgage backed securities until Mar 2010. However, they will be gradually slowing the pace of those purchases in order to promote a smooth transition in the markets.

Then they reiterated they would keep their options open.

The bond market and mortgage rates initial response was very positive, then went on a roller coaster ride. 

The bond finished up + 9bps Wednesday evening, turning around what was a - 34bps loss just prior to the Fed meeting.  That means interest rates finished up a little better today from their 12:00 levels.
I think this activity of uncertainty will be the norm as we go through the remainder of this year. 

And because we know the Fed's program is an "artificial" rate lowering program and the subsidy is going to taper off and go away, I would put some serious thought into locking in a rate if you have a good benefit.