This isn't the first time I've called the low in mortgage rates, but it could be the last. The chart below shows the nationwide averages according to BanxQuote: currently 3.49% for conforming, and 3.68% for jumbo loans. Jumbo rates briefly dipped to as low as 3.55% last December. That could well prove to the be lowest level in my lifetime. All it takes for rates to move higher is continued economic growth, even if it's relatively sluggish. That would bring the Fed closer and closer to the end of its QE3 program, and the Fed is already hinting that they might well discontinue it before the end of this year, or as early as mid-year.
The Fed now owns about 11% of the nation's $9.5 trillion of home mortgages (data in the chart only goes up to the end of last year, but the Fed is still buying $40 billion of MBS per month). This is not likely to increase much before QE3 ends. I don't think that Fed purchases of MBS have resulted in any meaningful reduction in mortgage rates, but I could be wrong. In any event, the end of QE3 means that the Fed thinks the outlook for the economy is improving, and that should help dissuade the market from continuing to pile into and/or hold long-term, fixed-income securities that are trading very near all-time lows.
For investors it's a warning shot across the bow. For home buyers, it's "come and get it!"
And if I'm wrong and mortgage rates continue to decline, it's relatively easy and cheap to refinance.
UPDATE: I should add that with the deductibility of mortgage interest and inflation, a 30-yr fixed-rate mortgage is essentially free money. The CPI has averaged about 2.5% for the past 15 years, and most folks with a jumbo loan should be able to deduct about 35% of the interest. The after-tax interest cost would be about 2.5%, and subtracting inflation of 2.5% gives you zero.
There are of course downside risks. You would be exposed to a further decline in housing prices, another recession, and/or a bout of deflation. But if any or all of those happen, interest rates are likely to decline further, leaving open the possibility of refinancing.