A very good question and there are many many answers to this questions. You need to look at specific neighborhoods in the above counties to get answers and they will be different for each neighborhood. You can approximate at the country level, but you definitely cannot put this counties together. There are some neighborhoods where the prices went up during the 2007 and the beginning of 2008.
Generalizing (what I promised not to do, but cannot resist the temptation!), we all see more buyers activity now and should improve through summer, but I don't think it is sustainable throughout the end of the year. Again - you need to look neighborhood by neighborhood.
I don't know what your personal goals are as far as buying and selling but I hope this info helps.
Maybe you can reply and get more specific on a certain area. So we can help you better.
The neighborhoods that are most vulnerable are the ones that had more 100% purchases, and are generally in the less affluent areas. In addition, the further out the homes are, the higher the chance of price decline, exacerbated by the rising gas prices. With that said, homes in the best neighborhoods such as Almaden, Los Gatos, Saratoga, Cupertino, have continued to hold their value very well.
I believe the falling prices will simply bring more differentiation between the different areas. Just look at the correlation between prices and school scores and general affluence of the area.
And we cannot accurately tell if things have bottomed out until they already have and things are moving up. The same thing happened in 2003, when the market stopped after we went to war with Iraq. The first half of the year was a great buying opportunity, and by September we started having multiple offers and that lasted 3 years! People will always have real estate needs, and many folks have simply pushed it off with the rash of bad economic news. But it will come back.