In a short sale will the seller make any money off of the short sale?
Short sales generally, by nature, do not allow for the seller of a property to retain any of the proceeds of sale. They are for the most part, "out of the loop" when it comes to negotiating a final price, which must be acceptable to their primary lender. Once a determination has been made by the seller to expose their home to sale for less than the amount they owe, most of the decision making process is handled by the lender. In some instances, a seller may be able to negotiate some "moving expenses" or small amount of cash to cooperate with the process.
At this point in time,(April 2008) short sales are becoming widespread as the country goes through a downturn in housing values.
A word of caution; a short sale does not guarantee that the buyer is buying the home below market price, it simply implies that the current owner owes on his/her mortgage more than the contracted price.
Your real estate agent should be versed in dealing with the extra steps involved in a short sale, and if they have not handled one before, you may want to consider finding a more seasoned professional to assist you in your search if there are many homes on the market in your area listed with clues on the listing like "subj to bank approval". It is not uncommon for a lender who may be swamped with short sale offers to take several weeks to approve your offer, if at all.