I believe that the seasonal strength remaining in some areas this Spring will be a faint memory by September.
I anticipate that for SD county the bulk of the price drops in the area-wide numbers (e.g. median and Case-Shiller) will take place in 2007 and 2008. Looking back to the last downturn, the largest price declines were a couple years after the peak. We are entering that period now in San Diego.

It will look like a sharp decline in terms of the numbers, but as many here have noted, the changes in median price in this cycle has lagged the changes in similar house comparisons. I view the next 2 years as the reports finally catching up.