In particular, Krugman's extended piece is able to take the time to rebut against the most common misunderstandings (and misinformation) about how the current economy picks its winners and losers, and why.
One we already know about: The Great Education Myth. Krugman lists, and debunks, several others as well.
More to the point, Krugman shows that it's not merely about who gets the most yachts to water ski behind or the most plasma TVs; it's about the integrity of our political system itself.
A generation ago the distribution of income in the United States didn't look all that different from that of other advanced countries. We had more poverty, largely because of the unresolved legacy of slavery. But the gap between the economic elite and the middle class was no larger in America than it was in Europe.
Today, we're completely out of line with other advanced countries. The share of income received by the top 0.1 percent of Americans is twice the share received by the corresponding group in Britain, and three times the share in France. These days, to find societies as unequal as the United States you have to look beyond the advanced world, to Latin America. And if that comparison doesn't frighten you, it should.
As a general rule, the more the gap between haves and have nots increases in a society, the more corrupt that society becomes.
Krugman's article is going onto the Readings list in the sidebar.