As of version 6.0, ButtonStyle has been superseded by the more general option BaseStyle.
As of Mathematica 7, ChebyshevDistance is superseded by ChessboardDistance.
As of Version 6.0, ClipFill has been superseded by the more general option ClippingStyle.
As of Version 6.0, ColorOutput has been superseded by ColorFunction, ColorData, and related functions.
ColumnForm has been superseded by the more general function Column.
As of Version 6.0, ContourGraphics has been superseded by GraphicsComplex and related functionality.
As of Version 6.0, ContourLines has been superseded by settings for ContourStyle.
As of Version 6.0, ConversionOptions is superseded by capabilities in Import and Export.
Date
(Obsolete Mathematica Symbol) Date has been superseded by DateList since Version 6.0.
As of Version 6.0, DefaultColor has been superseded by the more general option BaseStyle.