Hello Ben Hayat,
I would like to thank you for the feedback as it is an invaluable part of improving on our controls and their presentation. That said I would like to share a bit of information as to why we have decided to change the theming of the online demos.
The themes are indeed an integral part of Telerik controls, however they are in no way related to their functionality. Every example in the demos works in exact same way with every theme. Furthermore, when building an application, more often than not you will have a context, an overall design, maybe some branding guidelines. You will want it to look cool therefore in real world you choose a theme and you stick to it. And that is exactly what we did. After a lot of thought and analysis we decided to focus on functionality of the controls and chose Windows 7 theme as the one which will best fit the new demos app. This also helps us achieve what is, in my opinion, the best presentation of Silverlight controls on the market to date.
We currently have no plans of returning to the old ways but we do have plans of improving on our themes presentation.
the Telerik team