The Simple Skin will not be lost irreversibly -- it will just be taken out from the skins assembly. Instead it will live in the Skin Exchange portal, or why not even in a public repository.
In addition, we'll provide skin developers with the ability to create new skins faster -- namely, explaining more about the Sass files we are using.
Point taken for the business like skin, or a skin that allows for simple and powerful leverage.
the Telerik team
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the RadControls for ASP.NET AJAX, subscribe to their blog feed