Short sale of home similar to foreclosure in its effect on FICO score - latimes.com: "the affects of a short sale are similar to that of a foreclosure, which would cause someone with a 780 score on the 300-to-850 FICO scale to lose 140 to 160 points. People with higher scores tend to lose more points to a black mark than people with lower scores, so you can pretty much assume that your scores will drop from excellent to near-subprime territory for a while.
Exactly how long your score will take to recover is another mystery, although you'll start to see gradual improvements if you handle your other credit accounts responsibly. Your scores could climb back into 'good' territory (over 700) within a couple of years, but you may not regain your lofty peak until the short sale falls off your credit reports in seven years.
You also should be cautious about any agreement you sign with your lender. Some short sale agreements don't address what happens to the unpaid debt, while others specifically keep you on the hook for any deficiency balance (the difference between what you owe and the price the home"