I made a quick pass at this today. Didn't get too far, but it handles the drag and drop, and adds the chart to the page. At the moment, its not resizing the graph to the correct size (there are 4 set drop areas), but I don't think that would be too much work past what I'm doing now. Its a start anyway.
It was my first time playing with the drag and drop controls so most of that code stucture is based off the Telerik demos. You'll see I have 4 custom UserControls: BarGraph, BarGraph2, LineGraph, LineGraph2. These controls could be any telerik control and be tied to any data source, I just went the easy route for the quick example.
Hope this helps and I'll probably take a look at this again to make it much cleaner and hold some more functionality, but there are some other pressing projects I need to do first.
Is there an easier way to share files on the forum? Right now I've uploaded this to my photography site, but I wasn't sure if we were able to post sample projects in some way or not.