Bryant's message below is one that I have had to share with homeowners seemingly thousands of times over the past 6 years. He's got a "cut to the point" manner about him that makes a strong case for signing the promissory note.
I've got news for ya. You already did. When you purchased the property. You signed two documents. The mortgage. That created the lien and gave the lender the right to foreclose on your property (their collateral). And, you signed a promissory note. That was/is your personal promise to pay back the money you borrowed.
The Short Sale releases the lien (mortgage). It may or may not release you from the note. If the Lender is offering to swap out your $200,000 note, that you already signed, for a $10,000 at ZERO interest over 10 years then......why not sign and be done with it?
Think about it before you answer. Consult with an attorney. Then make the decision that works for you. Just don't say "I ain't signing no frickin' note!!!" without thinking it through. Make sense?