All the functionality in Algebra`Quaternions` is available in the newly created Quaternions Package.
All the functionality in Calculus`VectorAnalysis` is now available through the newly created Vector Analysis Package.
DiscreteMath`IntegerPartitions` was available as an add-on package in previous versions of Mathematica and is now available on the web at ...
As of Version 7, the Histograms Package has been integrated into the Mathematica kernel.
The functionality in Miscellaneous`Audio` is now available through the newly created Audio Package.
Much of the functionality in Miscellaneous`CityData` is now available in the built-in Mathematica kernel function CityData.
All the functionality in Miscellaneous`WorldData` is now available in the built-in Mathematica kernel function CountryData.
All the functionality in NumberTheory`PrimeQ` is now available through the newly created Primality Proving Package.
All the functionality of NumericalMath`SplineFit`is now available in the newly created Splines Package.
All functionality is available in the newly created Hypothesis Testing Package.