I actually made an automatically updating chart for this using FRED data: http://financial-charts.effingapp.com

TLDR: The correlation did go down a bit since publishing but still seems alright.

If you're looking for The Single Greatest Predictor of Future Stock Market Returns[1], here it is: http://www.philosophicaleconomics.com/2013/12/the-single-gre...

This is a long read, but it's worth it. The metric can be calculated in FRED[2], and as a predictor of future returns, it outperforms all of the most common stock market valuation metrics, including cyclically-adjusted price-earnings (CAPE) ratio[3]. (Basically, the average investor portfolio allocation to equities versus bonds and cash is inversely correlated with future returns over the long-term. This works better than pure valuation models because it accounts for supply and demand dynamics.)

[1]: http://www.philosophicaleconomics.com/2013/12/the-single-gre...

[2]: http://research.stlouisfed.org/fred2/graph/?g=qis

[3]: http://www.multpl.com/shiller-pe/