Housing bubble continues to deflate

The housing bubble continues its slow deflation (burst isn't quite the right word for this bubble).

WASHINGTON - Sales of existing homes plunged in March by the largest amount in nearly two decades, reflecting bad weather and increasing problems in the subprime mortgage market, a real estate trade group reported Tuesday.

I very much doubt we've seen the worst of this yet. So far, home prices have only fallen slightly. My guess is that has to change before we get over this. How much? I'm guessing 20% - 25% or so.