Implement Waterfall series type (http://en.wikipedia.org/wiki/Waterfall_chart).

Enable the TrackBallInfo to be vertically aligned (e.g. the bottom of the chart).

Make the StepLineSeries being able to plot a 'step' for a single point. Currently the StepLine series does not support drawing a single data point when it is in the beginning or the end of the ItemsSource. 

Add auto-range ability for the numeric axes that adjusts its range in accordance to the visible/zoomed data to show the data more clearly

Add mechanism in RadCartesianChart to change the axis origin position. Currently, you can position it only top, left, right or bottom. Add an option to position the axis at an arbitrary position on the opposite axis. For example, to position the horizontal axis in the middle of the vertical axis or at value lets say 3.

Add support for Tornado Chart. You can check this link for more information.

Sample Tornado Chart:

Add support for drill-down functionality.

Add ScatterRangeSeries visualization, similar to RangeSeries.

Add mechanism for getting the layout slot of the axis

Users should be able to create custom financial indicators.

ChartDataSource control should perform the sampling operation asynchronously in a background thread so that it is not blocking the UI thread.

Implement an indication for negative areas in a single AreaSeries/RangeSeries. For example the negative areas to be drawn in one color and the positive areas in another.

For more information on the visual representation you can take a look at the following blog post:
http://peltiertech.com/area-chart-invert-if-negative/

Allow to track points that intercept vertical line from mouse position (as now)  or points that intercept horizontal line from mouse position.
So allow to choose TrackDirection = Horizontal/Vertical

Thanks.
marc.

The stroke property of the PaletteEntry is not respected.

Numeric axes should be able to specify their PlotMode as categorical axes do (currently numeric axes use hardcoded OnTicks plot mode).