In some cases yes, in most cases no.

Lets start with the 30-year fixed rate mortgage. The 30-year fixed rate mortgage is not tied to short-term treasuries. Fixed mortgage rates are tied to long-term bond yields that move based on the outlook for the economy and inflation. True, even as the Fed has lowered rates, the 30-year fixed has come down, but that's because of the outlook for slower economic growth in the months ahead. While the decline in treasury yields has helped push mortgage rates lower, the decline in long term rates hasn't been in lockstep thanks to the fact that these mortgages are securitized and sold on the global market. Investors now demand a higher risk premium on these mortgages due to higher delinquencies and foreclosures.

Next lets take a look at 7 and 5-1 Adjustable Rate Mortgages (ARMs) Yes, this is good news if your 5-year (or 7 year) ARM is pegged to a treasury index.  So if you're facing a reset on, say, a $200,000 loan, you're now getting a payment increase of about $150 a month, as opposed to $370 a month, which you would have had before the Fed started cutting rates.

Do the Fed Rate Drops Help  Sub-Prime mortgage Holders?

 Nope. Unfortunately if you have a sub-prime ARM it is more than likely pegged to LIBOR, which has moved in the opposite direction. Because of the liquidity issues in global financial markets, LIBOR rates have actually increased at the same time that treasury and other benchmark yields have been declining, so the Fed lowering rates today would not help too many sub-prime mortgage holders.

How are Home Equity Lines of Credit Effected?

How about my Home Equity Line of Credit (HELOC): Yes, if you have that home equity line of credit that you used to renovate your bathroom/kitchen recently, then when the Fed lowers rates, your rate comes down as well. That's because HELOCs are predominantly pegged to the prime rate, which moves in step with the Federal Reserve.