Warren Buffett, Investment Marketer of the Year?

In his letter to shareholders last spring, Warren Buffett revealed that he had instructed his trustee to invest mostly in a very low cost S&P index fund. He recommended Vanguard's.

"in the five months that followed," the WSJ reports, "investors poured $5.5 billion into the Vanguard fund, or about three times more than during the same period the previous year."

Has indexing finally reached the tipping point and become the default way to invest?