I read that interview someplace.. He was talking about the proposed zero tax on dividends. He was making the point that people like himself could pay out huge dividends to themselves effectively dropping his tax rate to 3%.
He said that money he would potentially save in taxes would go further to help the economy if the same amount of money were spread around to thousands of "middle class" people... because they would spend the money, whereas he would just save it.
He didn't seem to point out that Berkshire Hathaway's Investments would benefit incredibly from a tax cut that favored middle class people rather than only the rich. Take a look at Berkshire Hathaway's Subsidiary Companies:
http://berkshirehathaway.com/subs/sublinks.html
He's famous for investing in companies like Coca-Cola, McDonalds, Gillette...