RadChart cannot show tooltips both on chart series and custom grid line.

CustomLine is rendered multiple times when zoom enough in. Setting AutoRange=false and/or SamplingThreshold does not seem to help.

REASON FOR DECLINATION
This is supported out-of-the-box by the new RadChartView.

Zooming & Scrolling is incorrect in datasets with clustered data and large gaps between the clusters.

Add support for gridlines and striplines for additional y axis.

There is a design time issue when binding to null collection with series mappings / itemmappings defined in XAML (MVVM).

Spline series is drawn incorrectly in scenarios where the data points are clustered in several spots along the XAxis with large gaps in-between.
Sample data:
Data Series Sample:
datetime / double:
21/01/2011 12:08:00AM / 10.0
21/01/2011 12:09:00AM / 16.0

REASON FOR DECLINATION
This is supported out-of-the-box by the new RadChartView.

It is currently possible to mousedown in a chart area, leave the RadChart with the mouse, and start interacting with other controls, and the RadChart will still await a mouseup event to stop Zooming / Scrolling. If a RadChart loses focus, it should resolve

Last AxisX label missing when manual axis range is set (the behavior is not consistent with the automatic axis range).

If you set the following style: 
<Style x:Key="XAxisGridLineStyle" TargetType="Line">
    <Setter Property="StrokeThickness" Value="12" />
    <Setter Property="Stroke" Value="Black" />
</Style>

you get grid lines 50% thinner then the desired (6px).

ShowPointMarks property in RangeSeriesDefinition does not work.

RadChart1.DefaultView.ChartLegend.LegendItemStyle = this.Resources["CustomLegendItem"] as Style; 
does not have effect when it is set on button click.

REASON FOR DECLINATION
This is supported out-of-the-box by RadLegend.

If the the datetime field is a nullable type, no matter if it has a value, it throws a null reference exception.

Implement Scatter 3D series type that can plot data again X-Y-Z coordinate system (real Z axis).

StrokeDashArray property does not apply to GridLines.

Chart: AxisX should allow a single item with AutoRange =false

Interactivity API does not work in constructor, Loaded and DataBound events.

Add multi-touch support for zoom/scroll, double tap, etc.

REASON FOR DECLINATION
This is supported out-of-the-box by the new RadChartView.

Chart: Allow AxisItem2D retemplating.

Expose HierarchyManager.Drill(...) method so the user can initiate drill-down action from code.

Expose public API for hover / highlight interactivity from code (currently hover action is triggered only if you physically move the mouse over the chart item).