Current P/E (trailing twelve month reported earnings): 20,25
Trailing P/E is a useful tool for understanding what has already happened in the market.
Shiller P/E (price divided by the average of ten years of earnings, adjusted for inflation): 26,30
The Shiller P/E is far more useful for calculating expected returns going forward.
On forward and estimated earnings the picture is a bit better, but it isn’t cheap (historical comparison). Analysts are currently expecting double digit growth for 2014 earnings.