Greg Mankiw brings a discussion from Michael Cox and Richard Alm that purports to say that inequality has not gotten that bad after all. Greg fails to bring the counterarguments but Mark Thoma has including another NY Times discussion from Paul Krugman:
Now, there’s no question that consumption inequality at a point in time is less than income inequality. But the CEX study on which they rely is widely believed to be seriously flawed, especially for tracking recent trends. For whatever reason, the survey seems to be missing a lot of consumption growth among the affluent.
Paul also links to a research paper on this topic by Robert J. Gordon and Ian Dew-Becker.