Hi Jason Elliott,
You could create a custom modules and use all features of the RadControls for ASP.NET AJAX. There were many internal discussions about how the 3.x backend should look and what to include. Ther are many pros and cons for each aspect and part of the backend. We have tried to use more AJAX and Web Services in Sitefinity 4.0 which CTP is available for downloading.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items.