As of Version 6.0, GraphicsSpacing has been superseded by the general option Spacings for GraphicsGrid and related functions.
GridBaseline has been superseded by the BaselinePosition option for Grid and related objects.
As of Version 6.0, HiddenSurface -> False has been superseded by the setting PlotStyle -> FaceForm[].
HTMLSave is superseded by Export[..., "HTML"] in Version 6.
As of Version 6.0, ImageRotated has been superseded by the "ImageTopOrientation" element specification.
As of Version 6.0, LongestMatch has been superseded by the pattern object Longest.
As of Version 6.0, MeshRange has been superseded by DataRange.
As of Version 6.0, NotebookCreate has been superseded by CreateDocument, CreatePalette, and related functions.
As of Version 6.0, OpenTemporary has been superseded by functionality in OpenWrite.
As of Version 6.0, PlotDivision has been superseded by MaxRecursion.