What is sustaining home values in our local market?

Over the past few weeks I have examined shifts in home values from several perspectives:

• The January 2009 Real Estate Market Report showed that even though sales activity has decreased, average and median sales prices are staying steady.
• I took a close look at "starter townhomes in Harrisonburg" and determined that home values in that segment of the market stayed relatively steady over the past year.
• I explained many different ways that we can evaluate and talk about home value trends.

But no matter how many times I looked at the data, I kept coming back to the fact that our market (Harrisonburg and Rockingham County) has not seen a significant drop in home values such as what has been seen in other parts of the state and country.

Why!????  This is the question that many people are asking --- why aren't we seeing a downward shift in values in this area?  Over coffee today, I was presented with one hypothesis (thanks Ian!) for why this may be occuring.  Ian's conjecture --- we're not seeing a big shift in values because there aren't too many people in our area that absolutely MUST sell, and thus they aren't making huge price drops in order to sell.

I can go along with this theory.  In talking to homeowners with their homes on the market, it seems that while there are many sellers who definitely, positively want to sell, the sooner the better, there aren't a very large number who are absolutely desperate and willing to take desperate measures in order to sell.

What are your thoughts?  Anyone want to refute or defend this theory?