The ability to select a series instead of a series' items.

There are scenarios where the actual minimum and maximum of the axis are of high importance but they are not displayed (due to TickOrigin). For instance if the axis range is (-1, 11) and TickOrigin is "0", the labels will be (0, 2, 4...) and "-1" and "11" will not be displayed. 

Expose RadFunnelChart and RadFunnelSeries for displaying funnel-like segments. They are usually used for visualizing stages in sales / marketing processes. 

Available in R3 2017 Official Release Version.
Check what's new in R3 2017 here: 
http://www.telerik.com/support/whats-new/wpf/release-history/ui-for-wpf-r3-2017

Will be available in Q1 2015 Release.

NullReferenceException on updating data when mouse is over chart's area and trackballinfo is visible. 

To workaround this, remove the TrackBallBehavior when data is updated and add it again on MouseMove.

Offset appears when chart with no margins and paddings is exported.

All labels of the LogratihmicAxis display 'zero' in scenarios with small values  (for example: 0.000000000116 or 2.3E-10)

CategoricalSeriesDescriptor.TypePath is not currently bindable. This means this has to point to a property on your DataSource that returns Telerik series types. This breaks the MVVM design model, as the DataSource points to the ViewModel, that should not contain any View specific types. Please provide a bindable alternative, such that a Converter can be applied to supply the View specific types.

Will be available in Q1 2016 Release.

XAML Team recently reviewed this request and decided not to address it in the future since the Smart Labels functionality was introduced in Q1 2014.

Implement Label Fit Mode In the polar chart to avoid label overlapping.

Incorrect drawing of BarSeries with negative values and additional axis.

This happens when we have one series with only positive values and one with mixed values.

Introduce Annotations ItemsSource property

Available in Release Version Q1 2016.

When setting MajorTickInterval, the actual interval used in display is adjusted when zooming to show a reasonable number of ticks. However, if LabelInterval is used along with it to achieve the desired number of labels on the chart, LabelInterval is not adjusted along with MajorTickInterval, resulting in too many or too few labels being displayed. Moreover the automatic adjustment of MajorTickInterval cannot be disabled, leading to problematic label display that cannot easily be handled by the developer without inside knowledge of the algorithm. 

Nice features would be:
- Adjust LabelInterval along with MajorTickInterval to keep approximately the same number of labels on the chart.
- Given the above, add an option to allow the Chart to determine the optimal MajorTickInterval and LabelInterval by itself (currently if MajorTickInterval is not specified, it displays ALL category ticks which can be way too many for the display)
- Add an option to disable the MajorTickInterval automatic adjustment if the programmer wishes to handle this manually

This suggestion arose out of this forum thread, which includes an example demonstrating the issue:

http://www.telerik.com/forums/majortickinterval-trouble-when-zooming

Bar series with DateTimeContinuousAxis axis with no MajorStep specified. When you zoom the bars gets to big and does not stay within its tick boundaries.

Add RangeSeriesDescriptor

Add support for 3D Surface Series Type.

This feature is now available as part of the ChartView control since R3 2016 Official release. Refer to the link below for more information.
http://docs.telerik.com/devtools/wpf/controls/radchartview3d/series/surfaceseries3d.html