Upgrading from:

Statistics`StatisticsPlots`

All functionality is available in the newly created Statistical Plots Package.
SymbolShape and SymbolStyle options are replaced by PlotMarkers.
PlotJoined option is replaced by Joined.
BoxOutlierShapes is replaced by BoxOutlierMarkers.

Load StatisticalPlots` to use the Statistical Plots Package functionality:

Version 5.2 << Statistics`StatisticsPlots`;
BoxWhiskerPlot[{1, 5, 2, 10, 3, 2, 5, 4}]

Joined replaces the PlotJoined option:

Version 5.2 << Statistics`StatisticsPlots`;
ParetoPlot[{a, b, a, a, c, b, c, a}, PlotJoined -> True]

Use nondefault outlier markers:

Version 5.2 << Statistics`StatisticsPlots`;
BoxWhiskerPlot[{1, 5, 2, 10, 3, 2, 5, 4}, BoxOutliers -> Automatic, 
 BoxOutlierShapes -> PlotSymbol[Triangle]]