Interesting front page article in the Weekend Wall Street Journal:  Their Income Up, U.S. Rich Yield A Tax Windfall; Surging Receipts Prompt Lower Deficit Projections, Debate Over Bush Tax Cuts, by Deborah Solomon:

As America’s rich get richer, the taxes they pay on their increasing income is yielding a windfall for the U.S. Treasury. The Bush administration and its supporters point to a recent surge in tax receipts as vindication of the 2001 and 2003 tax cuts that critics say favored the wealthy. And even opponents of the tax cuts acknowledge that the surge in unanticipated revenue is coming from the rich.

With wealthy Americans taking an increasing share of total household income and paying a greater share of total taxes, "what we’re seeing is a repeat of the late ’90s, where you get a flood of tax revenues from the hyper-rich," said Rudolph Penner, a former Congressional Budget Office director now at the Urban Institute think tank. "It may raise some worries socially, but it certainly is good for revenue."

The Treasury reported last week that tax receipts in April jumped 13.5% from a year earlier to $315.1 billion — much of that increase coming from taxes on investments and other sources of income more important to the wealthy. Receipts from these so-called nonwithheld taxes in April, a month when many tax returns are filed, were up about 17% from a year earlier. (Most Americans have the bulk of their taxes withheld from wages paid through the year.)