I read the article and I have to wonder if that was someone's high 'skool' thesis. Geez. The one bit of interesting data regarded affordability. And even the source of that tidbit said this (note the 'ways to go' part):
"Noting that the housing boom is even more heated in Canada, Great Britain and Japan, he suspects that the U.S. version has a ways to go."
But their other evidence was enrollement in RE classes and that one guy in one company sold some shares? THAT's the evidence of a bubble? If anything there are a few markets that cannot expect to maintain their price increases.