The credit markets are in the tank, and mortgage foreclosures are happening everywhere in today's economy. Whether voluntary or involuntary, it's important to understand that a foreclosure on your home will severely damage your credit score. In fact, a mortgage foreclosure will remain on your credit file for 7 years and will have a significant impact on your ability to borrow anything in the future.
It may not be quite as bad as a bankruptcy, but it will likely haunt you for a long time. It's a serious matter, so don't ignore it. Open the mail you receive from the bank, follow their instructions, and make the time to do everything you possibly can to negotiate an alternative to foreclosure.