As far as I have been told any module is allowed to use wrapped controls within the core framework, there are plans to provide a number of it (e.g. a new data picker). If module developers want to use other Telerik controls, they need an own developer license (or get DNN PE, which includes a license as well). AFAIK, the RAD editor will be part of DNN PE, while default editor for CE will remain FckEditor (the team is already working on new versions and incorporating CkEditor 3).

Looks like the included Telerik assembly in 5.2 has the RadEditor in it. It worked when I did a quick test. However  I reverted back to my licensed version as I know it works and there will be no surprises.

I don't know what the license terms are for 5.2 and Telerik's controls within regular DNN use at hosting companies, or when inside Visual Studio (design mode) or how it can be used if you're developing your own modules. The corp should have been very specific about the terms of use of Telerik's controls when 5.2 was released. People are just confused now.

Actually I was surprised the assembly was included. There was talk it was going to be included post 5.2. There needs to be an official announcement from the corp to clear up the matter.