Are We There Yet?

Late last year, some economists were saying the real estate market would start bouncing back by the middle of 2007. That hasn't happened yet. Why?
According to the Wall St. Journal, contributing causes include:

• inventories of unsold houses that have continued to grow (in part because of buidler speculation), and
  
• a surge in mortgage defaults, which has made lenders much more reluctant to grant credit to people with spotty payment histories
  

So when will this worse-than-expected slump end? It's hard to predict, but many feel that the bottom is near.