You are right that in Silverlight 2 it is not possible to do this transformation for arbitrary FrameworkElements. At this time, the CoverFlow control supports only images, but we are planning to extend this functionality with the forthcoming editions of the controls and the framework. You are getting loading images, because the CoverFlow is searching for either Image, ImageSource, URI or string that represents a URI.
If you have further questions, don't hesitate to ask us.
the Telerik team
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