Every XCategory label needs to be replaced with different icon.

Implement click events on the series items labels.

It is not possible to have striplines when the major Y axis is not used. Styling problems. ChartArea.AxisY.Visivility = Visibility.Collapsed - hides both primary and additional axes.

In Silverlight 4 RadChart doesn't get the right theme resources. See the attached project.

Horizontal Line Chart with Multiple X Axes - ticketId: 314652

Chart: X axis does not zoom under certain configuration, involving CollectionIndex

Cannot hide Y axis while leaving striplines visible.

Allow toggling the visibility of a series by clicking an item in the legend.

Double clicking the slider should toggle between actual range and full range.

Add DateTimeToDoubleConverter so Axis.MinValue / Axis.MaxValue can be set conveniently in XAML as DateTime strings.

Add RotationAngle property so series item labels can be rotated wih C# / VB.NET code.

Allow for rendering multiple nested pie/doughnut series together.

Add more google financial style features so the zoom control can be overlayed on a chart.

http://www.google.com/finance?q=INDEXDJX:.DJI,INDEXSP:.INX,INDEXNASDAQ:.IXIC

Add loading indicator / IsBusy support for RadChart.

Implement Box and Whisker 2D (boxplot) type in RadChart.

In some scenarios you have to graph some non-linear functions, e.g. exponential, 1/y.  It would be nice if there were integrated support how to specify this.