I've confirmed this behavior as well. The UI of the swapped out field should appear just as the Overview field below it (see screengrab). 

![studio-settings-no_editor](https://f.cloud.github.com/assets/163763/2070341/72a275f2-8d1a-11e3-96fc-ebc7e64f0e93.png)


Ideally, there should be UI text (.tip or .tip-stacked) to communicate that HTML is welcome in the editor.