I started seriously worrying about the crash back in 2004 [1], and while I was wrong about a lot of details (not least, ahem, the result of the 2004 US presidential election), I was bang-on about the underlying problem. What eventually surprised me was just how long the bubble was able to continue inflating before it finally popped.

[1] http://www3.sympatico.ca/taylormcgreal/thecomingcrash.html