Actually some areas may have, but there are many areas where the home values are holding or picking up. It's a broad question and would depend on the neighborhood and location of the property. Values of the homes are dependent upon the sale prices of homes of similar size, age, etc.
They did go down a little but not very much. It depends on the area and the appraiser.
What some people don't realize is that although everyone wants a good deal, those good deals can hurt area values. That's when a good appraiser comes in to look at properties that are more comparable in condition, age and size. I know of some people that have gotten inflated appraisals in 2007 and 2008 and when their house is appraised now is seems like a big loss but it shouldn't have been valued at that much to start with.
Many homes that have sold recently have actually shown significant appreciation. It will depend on several factors like location and condition. If you're working with a Realtor, they should be able to run a comparative market analysis for the property you're interested in which will help guide you on price. Feel free to contact me directly to learn more about the Opelousas market or to get information on a particular home.