Is mortgage rate 'magic number' low enough?

Mortgage rates have made a noticeable decline from peaks in the high-7% range last fall, and the housing market is abuzz in the wake of this week's Federal Reserve benchmark rate cut. Home sales have been lethargic: They're down 4.2% from where they were a year ago, according to newly released data from the National Association of Realtors. "Historically, 6% is a very…