Short sales and foreclosures are different animals altogether. One advantage of a short sale versus a foreclosure is that the buyer will recieve a full warranty deed with a short sale but not in a foreclosure. However, the advantage of a foreclosure is that the property owner is the bank and they can accept or reject an offer immediately, so you can usually close in a normal time frame, assuming there are no issues with the title search. Usually, for investors, foreclosures are the way to go but for occupants they can be too much risk and you're better off looking at conventional sale or if you can wait for one, a short sale.
As far as list to sale ratio is concerned on foreclosures often banks are getting asking price or in many cases over list price. They list them right and drive the bids up in order to generate multiple offers and sell in a short time frame. Honestly, conventional sellers could learn a lesson about pricing property from the banks, because by listing them right, banks are often able to get more money for the property then they would've if they started high and reduced several times.
On short sales, sometimes the lender will give the sellers an approved short sale price and depending on that lender, won't take a penny less than that price. Other times you can negotiate for a better deal. A key factor in determining the likilihood of a bank being wiling to negotiate is how long the property has been on the market at the price its currently listed for. Shorter time on market gives you less negotiationg room. Longer time to market and the bank will probably listen to reason. Negotiating in short sales really depends on the lender and their underwriting standards. Each lender is different and some are easier than others to work with on short sales.