Currently GCB loads an image block in tinymce's visual editor to make it easier to identify on the page.
Would love to have GCB render the content - at least for html code types - so users with little knowledge of HTML can verify the full page before updating. Might need to render as an un-editable block to prevent user from breaking the page - similar to the way DreamWeaver displays included files in Design View.
Icing on the cake... I don't know anything about Moxiecode's API's but it would be so cool if the user could click on the image to update the GCB, then refresh the tinymce visual editor to verify the revised content before updating the page.