Home mortgage rates dropped to a 52-year low this week

The Federal Reserve said that it would buy an additional $750 billion in mortgage-backed securities and $300 billion of long-term Treasurys. The so called "quantitative easing" policy essentially increases the money supply and is designed to push interest rates down, making borrowing cheaper.

Not much further to drop: Analysts say that while mortgage rates could edge a smidgen lower, they won't make any more dramatic plunges.