Thank you for the feedback.
The current skins implementation in RadControls "Prometheus" is very easy for users (you do not need to deploy an additional RadControls folder containing external scripts and skins) -- you only need a single DLL in your application without any external resources. For the majority of our customers this is a really simple approach.
The skinning mechanism is yet powerful and flexible for all guys like you who want to create custom skins (and change them dynamically). Please note that you do not necessarily need to register your custom skin in the page itself. You can choose to use ASP.NET themes and register your CSS files through the theming mechanism of the framework (and dynamically change the theme for the current user). Have you tried the approach we have described in this help article: http://www.telerik.com/help/radcontrols/prometheus/?ThemesHowTo.html
? (actually all topics in http://www.telerik.com/help/radcontrols/prometheus/
RadControls "Prometheus" Fundamentals -> Controlling Visual Appearance contain important skinning information)
So far we have only received positive feedback on the new skinning mechanism and will be happy to hear more input. Is the new mechanism usable for you? Does it simplify deployment for your apps? Do you feel that the custom skin registration (on the page or through ASP.NET Themes) works OK for you? Does anybody else think the "Classic" RadControls approach was better (and why)?
All the best,
the Telerik team