scottb, I do think part of the drop in revenue is the economy. And, for my site anyway, the months after the Christmas holiday season (Feb-May) have been the lowest paying. Still, the recent Google changes have caused a significant drop in traffic and, as a result, drop in clicks and income.
If the trend continues, I'll no longer have the money to tweak or make improvements to my site like I have since the inception.
I'll pay my hosting fees and continue to write occasional articles to keep the Google Bot happy.