Generally RadGrid supports binding to WCF services as demonstrated in the following online example:
As long as the native services in SP that you have in mind can be configured as in the above example and will return the data in the format of the ordinary wcf servies, there should be no problem to binding the grid.
Still, we do not claim that RadGrid supports binding to native sharepoint services as that scenario is not currently within the roadmap of our development team and has not been tested.
the Telerik team
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