I was putting together a few numbers for my investments class and in my lecture notes I came across the often quoted figure of 10% as the long term return for large stocks. This figure is based on a very long time period that includes many bull and bear markets. However, the past 11 years have been pretty much flat as far as price growth goes (I'm ignoring dividends). Take a look at this sobering graph which I grabbed from google finance.
In April 1999, the Dow was at about 10,000 which is roughly where it is today.