Fed Reservse rate slashes and the current mortgage rates?

Today, Federal Reserve slashes benchmark interest rate to between 0.25 and zero percent. What the heck does that mean? And how come no matter how many times the Fed slash the rate, it barely affects the 15-year and 30-year mortgage interest rates? Does it have something to do with the housing demand? Isn't the housing [...] http://bit.ly/mb4h3y