The waters aren't totally uncharted. The big aha moment for me was when I saw that . 10% higher than the peak of this boom! That kind of put it into a different context for me.
I think the biggest unknown is how the mortgage issue will play out. It could be worse than the last runup due to that, but I also see lots of people forecasting foreclosure rates that absolutely make no sense - so I take the doom and gloom scenarios with a grain of salt.