Factors working against million dollar 401ks:
-not introduced that long ago (80's)
-initially proposed as part of a 3 part retirement system (pension + 401k + SSI), so lower emphasis on contributing
-initial max contributions were less than half what they are today:
Google Answers: 401K Historical Chart
-since 2000 (when contribution limits have been higher, and more encouraged) the stock market has been close to flat, limiting the amount of growth of the larger contributions
-most Americans do not have the income to support maxing the 401k each year; if the median is around $45k, the average American would have to contribute 38% to max it out
-the workers who have been around long enough, making enough to max out the 401k each year, were likely more senior employees, who are now retiring and reducing their balances by taking distributions
I'm not too surprised the figures are that low - but I guarantee that they're on the rise. Like KTP said, it won't mean as much. I'd even venture to say, that a time will come (pretty soon in fact) where if you DON'T have $1 million, people will say you've done something wrong in your planning. Though that prob won't all be in the 401k...