Found this on the Financial Times. From the article:
"There are many definitions of a secular bear market, but a popular one is that a new secular bull market only starts once the previous peak has been taken out for good, in real terms."
I don't think this conclusively debunks the "top is in!" crowd, but it does help me realize that nominal charts make everything look like a bubble, when in fact much of what we are observing is the inverse of inflation.