The RadPropertyGrid columns should be able to auto resize according to their cells content.

Add the ability for custom sorting in the RadPropertyGrid.

Generic collections are used by entity framework to contain child objects.

UPDATE: RadPropertygrid uses the standard System.ComponentMode.Design.CollectionEditor when editing collections. The editor requirements are that the collection being edited implements the IList interface and that it has an indexer (Item in VB.NET) property. Entity Framework generates an ICollection<T> property which holds a HasSet<T> object. This does not fit both requirements of the editor and prevents it from working correctly.

Developers should be able to validate user input in the RadPropertyStore items.

UPDATE: Currently we have decided to stick with the current implementation where all the validation is done through the PropertyValidating/ed events.

Currently editors not shown as dialog do not work as the RadPropertyGrid editor is closed when focus is transferred to the dialog form.

Currently users can only specify a UITypeEditor. They should be able to specify which BaseInputEditor to be used for a given property when they edit it:
[Editor(typeof(PropertyGridBrowseEditor), typeof(BaseInputEditor)]
public string FilePath { get; set; }

Currently RadPropertyGrid does not handle the GetStandardValues method.

ADD. RadPropertyGrid - add custom grouping functionality

When you have  a property that is bool? or ToggleState, it would be good to have three-state functionality for the PropertyGridCheckBoxItemElement.

How to create a PropertyGrid and initialize it like this,modify the 'segments' arraies as I modify the 'count'

When a property has a TypeConverter which method GetStandardValuesExclusive returns false. Users should be able to enter additional values, other than the values returned by the GetStandardValues mehtod.

Add the ability to handle collection items in the RadPropertyGrid.

When the spin editor is opened in the RadPropertyGrid the default min and max values should be the min and max values of the type of the property that is being edited.

Currently when expanding an item in RadPropertyGrid the order of the sub items changes on every start.

The RadPropertyGrid editing mechanism can be improved by adding ValueChanged/ing events similar to those in RadGridView.

When applied to a property the editor for this property should show its text as a password.

Extend the sorting functionality in order to support custom sort order.

More specifically the behavior when the combobox editor is double clicked it changes its current item to the next one.