I want to emphasize, that the separation of the assemblies will neither lead to more requests to the server,nor it will affect the deployment of your application. This is due to the fact that Silverlight apps are deployed as a single XAP file that contains all the needed assembly references and resources.
We would greatly appreciate your feedback about this change. Drop us a line and let us know what you prefer - one monolithic assembly, or separate assemblies for every control. We will implement the above mentioned change in the next couple of days. Any suggestions and comments are welcome.
Valentin Stoychev (@ValioStoychev) for long has been part of Telerik and worked on almost every UI suite that came out of Telerik. Valio now works as a Product Manager and strives to make every customer a successful customer.