Look at the interest rates today, September 2010. With interest rates as low as 4.375% on a 30 year mortgage, your monthly payment on a $100,000 loan would be about $500 per month. Just a few weeks ago interest rates were at 6%. The monthly payment at 6% would have been $600 per month.
What are you going to do, wait until spring and pay the extra $100 per month? It's your money.