Do the price of higher end homes continue to drop or the housing slump just effecting lower and middle priced homes?

In our area its really only the higher end houses that have been hit hard.  Once you get over the $300k range, houses are off 20% +.  On the other hand, in the entry level range prices have held relatively flat if not up a bit. 

This is Texas mind you, and our real estate market seems to be a lot more robust than what I'm hearing from the rest of the country.